VANGUARD MONEY MARKET RESERVES INC
485BPOS, 2000-03-08
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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                   FORM N-1A

                   REGISTRATION STATEMENT (NO. 2-52698) UNDER
                           THE SECURITIES ACT OF 1933

                           PRE-EFFECTIVE AMENDMENT NO.

                        POST-EFFECTIVE AMENDMENT NO. 58
                                      AND

               REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY
                                  ACT OF 1940

                                AMENDMENT NO. 60

                         VANGUARD MONEY MARKET RESERVES
        (EXACT NAME OF REGISTRANT AS SPECIFIED IN DECLARATION OF TRUST)

                     P.O. BOX 2600, VALLEY FORGE, PA 19482
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICE)

                  REGISTRANT'S TELEPHONE NUMBER (610) 669-1000

                           R. GREGORY BARTON, ESQUIRE
                                  P.O. BOX 876
                             VALLEY FORGE, PA 19482

              IT IS PROPOSED THAT THIS AMENDMENT BECOME EFFECTIVE:
   ON MARCH 24, 2000, PURSUANT TO RULE 485(B) OF THE SECURITIES ACT OF 1933.

                 APPROXIMATE DATE OF PROPOSED PUBLIC OFFERING:
  AS SOON AS PRACTICABLE AFTER THIS REGISTRATION STATEMENT BECOMES EFFECTIVE.



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<PAGE>

                                                            VANGUARD(R)
                                                            MONEY MARKET
                                                            FUNDS

                                                            Prospectus
                                                            March 24, 2000

This  prospectus  contains
financial data for the
Funds through the
fiscal year ended
November 30, 1999.

VANGUARD PRIME
MONEY MARKET FUND

VANGUARD FEDERAL
MONEY MARKET FUND

VANGUARD TREASURY
MONEY MARKET FUND

                                                        [MEMBERS OF
                                                        THE VANGUARD GROUP LOGO]
<PAGE>

VANGUARD MONEY MARKET FUNDS

Prospectus

March 24, 2000




- --------------------------------------------------------------------------------
   CONTENTS
- --------------------------------------------------------------------------------

 1 FUND PROFILES                            16 FINANCIAL HIGHLIGHTS

   1 Vanguard Prime Money Market Fund       18 INVESTING WITH VANGUARD

   4 Vanguard Federal Money Market Fund        18 Services and Account Features

   7 Vanguard Treasury Money Market Fund       19 Types of Accounts

10 MORE ON THE FUNDS                           20 Buying Shares

13 THE FUNDS AND VANGUARD                      22 Redeeming Shares

13 INVESTMENT ADVISER                          26 Transferring Registration

14 DIVIDENDS AND TAXES                         26 Fund and Account Updates

15 SHARE PRICE                              GLOSSARY (inside back cover)

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- --------------------------------------------------------------------------------
WHY READING THIS PROSPECTUS IS IMPORTANT

This prospectus  explains the objective,  risks,  and policies of Vanguard Prime
Money  Market,  Federal  Money  Market,  and  Treasury  Money Market  Funds.  To
highlight  terms and  concepts  important  to  mutual  fund  investors,  we have
provided "Plain Talk(R)" explanations along the way. Reading the prospectus will
help you to decide  which  Fund,  if any,  is the right  investment  for you. We
suggest that you keep it for future reference.

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- --------------------------------------------------------------------------------
IMPORTANT NOTE

The Prime Money Market Fund offers two separate classes of shares:  Investor and
Institutional.  This prospectus offers the Fund's Investor Shares, which have an
investment  minimum of $3,000  ($1,000 for IRAs) and are intended for individual
investors. Please call Vanguard's Institutional Investor Group at 1-800-523-1036
to obtain a separate  prospectus  that offers the Fund's  Institutional  Shares,
which have an investment  minimum of $10 million and generally are not available
to investors who require special employee benefit plan services.
     The Fund's  separate  share classes have different  expenses;  as a result,
their investment  performances will vary. UNLESS OTHERWISE NOTED, ALL REFERENCES
IN  THIS  PROSPECTUS  TO  FEES,  EXPENSES,  AND  INVESTMENT  PERFORMANCE  RELATE
SPECIFICALLY TO INVESTOR SHARES.

- --------------------------------------------------------------------------------


NEITHER  THE  SECURITIES  AND  EXCHANGE  COMMISSION  NOR  ANY  STATE  SECURITIES
COMMISSION HAS APPROVED OR  DISAPPROVED  OF THESE  SECURITIES OR PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

<PAGE>

1

FUND PROFILE--
VANGUARD PRIME MONEY MARKET FUND

The following  profile  summarizes  key features of Vanguard  Prime Money Market
Fund.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests primarily in high-quality, short-term money market instruments,
including certificates of deposit,  banker's acceptances,  commercial paper, and
other  money  market  securities.  To be  considered  high  quality,  a security
generally must be rated in one of the two highest credit-quality  categories for
short-term  securities by at least two nationally recognized rating services (or
by one, if only one rating  service  has rated the  security).  If unrated,  the
security must be determined by the Fund's adviser to be of quality equivalent to
those in the two highest  credit-quality  categories.  The Fund will maintain an
average  maturity  of 90 days or  less.  For  more  information,  see  "Security
Selection" under MORE ON THE FUNDS.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential to hurt the Fund's performance, should be low for the Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION

The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.


<PAGE>

2


              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------

                              1990           8.27%
                              1991           6.14%
                              1992           3.74%
                              1993           3.01%
                              1994           4.08%
                              1995           5.82%
                              1996           5.29%
                              1997           5.44%
                              1998           5.38%
                              1999           5.01%
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 2.03%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.72% (quarter ended June 30, 1993).

        -----------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
        -----------------------------------------------------------------
                                           1 YEAR    5 YEARS   10 YEARS
        -----------------------------------------------------------------
        Vanguard Prime Money Market Fund    5.01%     5.39%      5.21%
        Salomon Smith Barney 3-Month
         Treasury Index                     4.74      5.20       5.05
        Lipper Money Market Fund Average*   4.49      4.88       4.73
        -----------------------------------------------------------------
        *Derived from data provided by Lipper Inc.
        -----------------------------------------------------------------

     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.11%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.22%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.33%


<PAGE>

3

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS    5 YEARS      10 YEARS
- -------------------------------------------------
    $34        $106       $185          $418
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                              MINIMUM INITIAL INVESTMENT
Declared daily and distributed on the  $3,000; $1,000 for IRAs and custodial
first business day of each month       accounts for minors

INVESTMENT ADVISER                     NEWSPAPER ABBREVIATION
The Vanguard Group, Valley Forge,      VangPr
Pa., since 1981
                                       VANGUARD FUND NUMBER
INCEPTION DATE                         030
June 4, 1975
                                       CUSIP NUMBER
NET ASSETS AS OF NOVEMBER 30, 1999     922906201
$41.2 billion
                                       TICKER SYMBOL
SUITABLE FOR IRAS                      VMMXX
Yes

- --------------------------------------------------------------------------------

<PAGE>

4

FUND PROFILE--
VANGUARD FEDERAL MONEY MARKET FUND

The following  profile  summarizes key features of Vanguard Federal Money Market
Fund.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests primarily in high-quality,  short-term money market instruments
issued by U.S. government agencies.  Most of the securities held by the Fund are
not backed by the full faith and  credit of the U.S.  government.  The Fund will
maintain  an average  maturity  of 90 days or less.  For more  information,  see
"Security Selection" under MORE ON THE FUNDS.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential to hurt the Fund's performance, should be very low for the Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION

The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.


<PAGE>

5

              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------

                              1990           8.07%
                              1991           5.96%
                              1992           3.68%
                              1993           2.98%
                              1994           4.03%
                              1995           5.77%
                              1996           5.24%
                              1997           5.38%
                              1998           5.31%
                              1999           4.94%
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 1.99%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.72% (quarter ended June 30, 1993).

        -----------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
        -----------------------------------------------------------------
                                              1 YEAR  5 YEARS   10 YEARS
        -----------------------------------------------------------------
        Vanguard Federal Money Market Fund     4.94%   5.33%      5.13%
        Salomon Smith Barney 3-Month
         Treasury Index                        4.74    5.20       5.05
        Lipper U.S. Government Money Market
         Fund Average*                         4.47    4.85       4.68
        -----------------------------------------------------------------
        *Derived from data provided by Lipper Inc.
        -----------------------------------------------------------------


     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.13%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.20%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.33%


<PAGE>

6

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS    5 YEARS      10 YEARS
- -------------------------------------------------
    $34        $106       $185          $418
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                              MINIMUM INITIAL INVESTMENT
Declared daily and distributed on the  $3,000; $1,000 for IRAs and custodial
first business day of each month       accounts for minors

INVESTMENT ADVISER                     NEWSPAPER ABBREVIATION
The Vanguard Group, Valley Forge,      VangFdl
Pa., since inception
                                       VANGUARD FUND NUMBER
INCEPTION DATE                         033
July 13, 1981
                                       CUSIP NUMBER
NET ASSETS AS OF NOVEMBER 30, 1999     922906300
$5.2 billion
                                       TICKER SYMBOL
SUITABLE FOR IRAS                      VMFXX
Yes

- --------------------------------------------------------------------------------

<PAGE>

7

FUND PROFILE--
VANGUARD TREASURY MONEY MARKET FUND

The following profile  summarizes key features of Vanguard Treasury Money Market
Fund.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests  solely in  high-quality,  short-term  money market  securities
whose interest and principal payments are backed by the full faith and credit of
the U.S.  government.  At least 80% of the Fund's assets will always be invested
in U.S. Treasury securities;  the remainder of the Fund's assets may be invested
in securities issued by U.S. government agencies or instrumentalities.  The Fund
will maintain an average maturity of 90 days or less. For more information,  see
"Security Selection" under MORE ON THE FUNDS.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential  to hurt the Fund's  performance,  should be  negligible  for the
     Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION


The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.


<PAGE>

8


              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------
                              1990           7.94%
                              1991           5.73%
                              1992           3.53%
                              1993           2.86%
                              1994           3.81%
                              1995           5.49%
                              1996           5.09%
                              1997           5.12%
                              1998           5.00%
                              1999           4.55%
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 1.96%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.69% (quarter ended June 30, 1993).

      --------------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
      --------------------------------------------------------------------
                                               1 YEAR  5 YEARS   10 YEARS
      --------------------------------------------------------------------
      Vanguard Treasury Money Market Fund       4.55%   5.05%      4.90%
      Salomon Smith Barney 3-Month
         Treasury Index                         4.74    5.20       5.05
      Lipper U.S. Treasury Money Market Fund
       Average*                                 4.23    4.74       4.64
      --------------------------------------------------------------------
      *Derived from data provided by Lipper Inc.
      --------------------------------------------------------------------

     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.14%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.19%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.33%


<PAGE>

9

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS    5 YEARS      10 YEARS
- -------------------------------------------------
    $34        $106       $185         $418
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                              MINIMUM INITIAL INVESTMENT
Declared daily and distributed on the  $3,000; $1,000 for IRAs and custodial
first business day of each month       accounts for minors

INVESTMENT ADVISER                     NEWSPAPER ABBREVIATION
The Vanguard Group, Valley Forge,      VangTrsy
Pa., since inception

INCEPTION DATE                         VANGUARD FUND NUMBER
March 9, 1983                          050

NET ASSETS AS OF NOVEMBER 30, 1999     CUSIP NUMBER
$4.6 billion                           921948105

SUITABLE FOR IRAS                      TICKER SYMBOL
Yes                                    VMPXX

- --------------------------------------------------------------------------------

<PAGE>

10

MORE ON THE FUNDS

The following  sections  discuss other important  features of the Vanguard Money
Market Funds,  including  market  exposure,  security  selection,  and costs and
market-timing.  You will also find  detailed  risk  information  about the Funds
throughout these sections.

MARKET EXPOSURE

Each  Fund's  primary  policy  is to invest in very  high-quality  money  market
instruments--also  known as cash reserves--that are considered  short-term (that
is,  they  mature  in 13 months or less).  Each Fund will  maintain  an  average
maturity of 90 days or less.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                            MONEY MARKET INSTRUMENTS

The term "money market  instruments"  refers to a variety of  short-term  liquid
investments,  usually  with a maturity of 13 months or less.  Some common  types
are:  Treasury  bills  and  notes,  which  are  securities  issued  by the  U.S.
government;  commercial  paper,  which  are  promissory  notes  issued  by large
companies or financial firms; banker's acceptances, which are credit instruments
guaranteed by a bank; and negotiable  certificates of deposit,  which are issued
by  banks in  large  denominations.  Money  market  securities  can pay a fixed,
variable, or floating rate of interest.
- --------------------------------------------------------------------------------

[FLAG] EACH FUND IS SUBJECT TO INCOME  RISK,  WHICH IS THE CHANCE  THAT A FUND'S
     DIVIDENDS (THAT IS, INCOME) WILL DECLINE BECAUSE OF FALLING INTEREST RATES.
     BECAUSE THE FUNDS' INCOME IS BASED ON SHORT-TERM INTEREST  RATES--WHICH CAN
     FLUCTUATE  SIGNIFICANTLY OVER SHORT  PERIODS--INCOME RISK IS EXPECTED TO BE
     HIGH FOR ALL THREE FUNDS.




SECURITY SELECTION

The Vanguard  Group,  adviser to the Funds,  selects  high-quality  money market
instruments.  Each Fund focuses on  securities  of a particular  class of issuer
(the U.S. government,  U.S. government agencies, or non-government issuers). The
Funds are managed without regard to tax ramifications.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                 CREDIT QUALITY

A money market  instrument's credit quality depends upon the issuer's ability to
pay interest on the security and,  ultimately,  to repay the debt. The lower the
rating by one of the independent  bond-rating agencies (for example,  Moody's or
Standard & Poor's),  the greater the chance (in the rating agency's opinion) the
security's issuer will default, or fail to meet its payment obligations.  Direct
U.S. Treasury  obligations  (that is, securities issued by the U.S.  government)
carry  the  highest  credit  ratings.  All  things  being  equal,  money  market
instruments with greater credit risk offer higher yields.
- --------------------------------------------------------------------------------

[FLAG] EACH FUND IS  SUBJECT  TO  MANAGER  RISK,  WHICH IS THE  CHANCE  THAT THE
     ADVISER MAY DO A POOR JOB OF SELECTING SECURITIES.


<PAGE>

11

     The Prime Money Market Fund invests  primarily in  certificates of deposit,
banker's  acceptances,  commercial  paper,  and other money  market  securities.
Commercial  paper must be rated Prime-1 by Moody's  Investors  Service or A-1 by
Standard & Poor's  Corporation.  Securities that are unrated must be issued by a
company  with a debt  rating  of A3 or  better  by  Moody's  or A- or  better by
Standard & Poor's.  The Prime  Money  Market  Fund also  invests  in  short-term
corporate,  state, and municipal obligations rated A3 or better by Moody's or A-
or better by Standard & Poor's,  and in securities that are considered  suitable
for the Federal Money Market Fund (see below).

     Among the certificates of deposit  typically held by the Prime Money Market
Fund are Eurodollar and Yankee obligations,  which are primarily certificates of
deposit  issued in U.S.  dollars by foreign  banks and foreign  branches of U.S.
banks. Eurodollar and Yankee obligations have risks similar to U.S. money market
instruments,  such as income risk and credit risk. Other risks of Eurodollar and
Yankee obligations include the possibilities that: a foreign government will not
let U.S.  dollar-denominated  assets  leave the  country;  the banks  that issue
Eurodollar obligations may not be subject to the same regulations as U.S. banks;
and adverse  political or economic  developments  will affect  investments  in a
foreign  country.  Before  the Fund's  adviser  selects a  Eurodollar  or Yankee
obligation,  however,  the  foreign  issuer  undergoes  the same  credit-quality
analysis and tests of financial strength as an issuer of domestic securities.

     The Federal  Money Market Fund invests  primarily in  securities  issued by
U.S. government agencies whose interest and principal payments are not backed by
the full faith and credit of the U.S. government.  These agencies include, among
others,  the Federal Home Loan Bank, the Federal National Mortgage  Association,
and the  Federal  Home Loan  Mortgage  Corporation.  The Fund also may invest in
securities  issued by the U.S.  Treasury and U.S. government  agencies  that are
backed by the full faith and credit of the U.S. government.

     The Treasury Money Market Fund invests solely in securities  whose interest
and  principal  payments  are  backed by the full  faith and  credit of the U.S.
government.  At least 80% of the Fund's  assets  will always be invested in U.S.
Treasury  securities.  The remainder of the Fund's assets may include securities
issued by U.S.  government  agencies,  such as the Government  National Mortgage
Association, the Small Business Administration, and the Federal Financing Bank.

[FLAG] EACH FUND IS SUBJECT,  TO A LIMITED EXTENT,  TO CREDIT RISK, WHICH IS THE
     CHANCE  THAT  THE  ISSUER  OF A  SECURITY  WILL  FAIL TO PAY  INTEREST  AND
     PRINCIPAL IN A TIMELY MANNER.

     The three Funds differ mainly in terms of credit risk.  In absolute  terms,
each Fund's credit quality is very high.

     In relative  terms,  the  Treasury  Money  Market  Fund,  which  invests in
securities  backed by the full faith and credit of the U.S.  government,  offers
the lowest credit risk--and generally the lowest yield--of the three Funds.

     Not all of the  securities  included in the Federal  Money  Market Fund are
backed by the full faith and credit of the U.S. government, and so the potential
credit risk and yield for the Fund are  somewhat  higher  than for the  Treasury
Money Market Fund.

     While the credit  quality of its  securities is very high,  the Prime Money
Market Fund faces more risk because it invests in money market securities issued
by private  companies.  It is possible  that one or more of these  companies may
experience financial  difficulties and, as a result, may fail to pay interest to
the Fund or return the Fund's  principal when repayment

<PAGE>

12

is due.  Therefore,  the Prime Money Market Fund offers the highest credit risk,
and generally the highest yield, of the three Funds.

     Bear in mind that,  while each Fund  invests in  high-quality  money market
instruments,  the three Funds are not insured or  guaranteed  by the FDIC or any
other agency of the U.S. government.

[FLAG] THE PRIME AND FEDERAL  MONEY MARKET FUNDS  RESERVE THE RIGHT TO INVEST IN
     REPURCHASE AGREEMENTS, WHICH ARE SUBJECT TO SPECIFIC RISKS.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                              REPURCHASE AGREEMENTS

A means  of  investing  money  for a short  period,  repurchase  agreements  are
contracts  in which a  financial  institution  sells  securities  and  agrees to
repurchase  the  securities on a specific date  (normally the next business day)
and at a specific price.

- --------------------------------------------------------------------------------

     Repurchase  agreements carry several risks. For instance,  if the seller is
unable to repurchase the securities as promised,  the Fund may experience a loss
when trying to sell the securities to another person.  Or, if the seller becomes
insolvent, a bankruptcy court may determine that the securities do not belong to
the Fund and order that the  securities  be sold to pay off the seller's  debts.
The Funds' adviser  believes that these risks can be controlled  through careful
security selection and monitoring.

[FLAG]  THE  FUNDS  RESERVE  THE  RIGHT  TO  INVEST,  TO A  LIMITED  EXTENT,  IN
     FLOATING-RATE SECURITIES, WHICH ARE TRADITIONAL TYPES OF DERIVATIVES.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                   DERIVATIVES

A derivative is a financial  contract whose value, or interest rate, is based on
(or "derived"  from) a traditional  security  (such as a stock or bond), a money
market  benchmark  (such  as U.S.  Treasury  bill  rates  or the  Federal  Funds
Effective  Rate),  an asset (such as a commodity  like gold),  or a market index
(such as the S&P 500 Index).
- --------------------------------------------------------------------------------

     A floating-rate  security's interest rate, as the name implies, is not set;
instead, it fluctuates periodically. Generally, the security's yield is based on
a U.S. dollar-based  interest-rate benchmark such as the Federal Funds Rate, the
90-day Treasury bill rate, or the London Interbank  Offered Rate (LIBOR).  These
securities reset their yields on a periodic basis (for example,  daily,  weekly,
or quarterly)  and are closely  correlated  to changes in money market  interest
rates.

     The Funds will not use derivatives for speculative purposes or as leveraged
investments that magnify the risks of an investment.

     In  addition,  each Fund may invest up to 10% of its net assets in illiquid
securities. These are securities that cannot be readily resold or converted into
cash.

COSTS AND MARKET-TIMING

The Vanguard Money Market Funds serve both short- and long-term  investor needs;
however,  other  Vanguard  funds are  intended  for  long-term  investors  only.
Investors  who  engage  in  excessive   in-and-out   trading  activity  generate
additional  costs that are borne by all of a fund's  shareholders.  To  minimize
these costs, Vanguard's stock, bond, and balanced funds

<PAGE>

13

have adopted policies to discourage short-term trading--which includes switching
back and forth from the Vanguard Money Market Funds. Please check other Vanguard
funds'  prospectuses  for specifics on the trading  limitations  of those funds.
Also, all Vanguard funds, including the Money Market Funds, reserve the right to
stop offering shares at any time or to reject specific purchase requests.

     THE  VANGUARD  FUNDS DO NOT  PERMIT  MARKET-TIMING.  DO NOT INVEST IN THESE
FUNDS IF YOU ARE A MARKET-TIMER.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                      VANGUARD'S UNIQUE CORPORATE STRUCTURE

The Vanguard Group is truly a MUTUAL mutual fund company. It is owned jointly by
the funds it oversees and thus  indirectly by the  shareholders  in those funds.
Most other mutual funds are operated by for-profit management companies that may
be owned by one person,  by a group of individuals,  or by investors who own the
management  company's stock. By contrast,  Vanguard  provides its services on an
"at cost"  basis,  and the funds' expense  ratios  reflect only these costs.  No
separate  management  company reaps profits or absorbs losses from operating the
funds.
- --------------------------------------------------------------------------------

THE FUNDS AND VANGUARD

The Funds are members of The Vanguard Group, a family of more than 35 investment
companies  with more than 100 funds holding assets worth more than $520 billion.
All of the  Vanguard  funds  share  in the  expenses  associated  with  business
operations, such as personnel, office space, equipment, and advertising.

     Vanguard  also  provides   marketing   services  to  the  funds.   Although
shareholders do not pay sales commissions or 12b-1  distribution fees, each fund
pays its allocated share of The Vanguard Group's marketing costs.

INVESTMENT ADVISER

The Vanguard Group (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, founded in
1974,  serves as the  Funds'  adviser  through  its Fixed  Income  Group.  As of
November 30, 1999,  Vanguard  served as adviser for about $354 billion in assets
including more than 40 Vanguard funds.  Vanguard manages the Funds on an at-cost
basis, subject to the control of the Trustees and officers of the Funds. For the
fiscal year ended November 30, 1999, the investment  advisory  expenses for each
Fund  represented  an effective  annual rate of 0.01% of each Fund's average net
assets.

     The  adviser  places  all orders  for the  purchase  and sale of the Funds'
securities,  and seeks out the best available price and most favorable execution
for all transactions.


<PAGE>

14

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                               THE FUNDS' ADVISER



The individuals responsible for overseeing the Funds' investments are:

IAN A.  MACKINNON,  Managing  Director of Vanguard and head of Vanguard's  Fixed
Income  Group;  has  worked  in  investment   management  since  1974;   primary
responsibility for Vanguard's  internal  fixed-income  policy and strategy since
1981; B.A., Lafayette College; M.B.A., Pennsylvania State University.

ROBERT F.  AUWAERTER,  Principal  of Vanguard  and Fund  Manager;  has worked in
investment  management since 1978; has managed portfolio investments since 1979;
B.S., University of Pennsylvania; M.B.A., Northwestern University.

JOHN HOLLYER,  Principal of Vanguard and Fund Manager;  has worked in investment
management  since 1987;  has managed  portfolio  investments  since 1989;  B.S.,
University of Pennsylvania.

DAVID  R.  GLOCKE,  Principal  of  Vanguard  and Fund  Manager;  has  worked  in
investment  management since 1991; has managed portfolio investments since 1997;
B.S., University of Wisconsin.

Mr.  Auwaerter,  Mr.  Hollyer,  and Mr.  Glocke manage the Funds on a day-to-day
basis.  Mr.  MacKinnon is  responsible  for setting the Funds' broad  investment
policies and for overseeing the Fund Managers.
- --------------------------------------------------------------------------------

DIVIDENDS AND TAXES

FUND DISTRIBUTIONS

Each Fund distributes to shareholders  virtually all of its net income (interest
less expenses).  The Fund's income dividends accrue daily and are distributed on
the first business day of every month.  You can receive your income dividends in
cash, or you can have them automatically reinvested in more shares of the Fund.

BASIC TAX POINTS

Vanguard will send you a statement  each year showing the tax status of all your
distributions.  In addition,  taxable investors should be aware of the following
basic tax points:

- -    Distributions are taxable to you for federal income tax purposes whether or
     not you reinvest these amounts in additional Fund shares.

- -    Distributions   declared  in  December--if  paid  to  you  by  the  end  of
     January--are  taxable  for  federal  income tax  purposes as if received in
     December.

- -    Any  dividends  that you receive are taxable to you as ordinary  income for
     federal income tax purposes.

- -    Dividend  distributions  that you receive may be subject to state and local
     income  taxes.  Depending on your state's  rules,  however,  any  dividends
     attributable to interest earned on direct  obligations of the U.S. Treasury
     may be exempt  from state and local  taxes.  Vanguard  will notify you each
     year how much, if any, of your dividends may qualify for this exemption.


<PAGE>

15


GENERAL INFORMATION

BACKUP  WITHHOLDING.   By  law,  Vanguard  must  withhold  31%  of  any  taxable
distributions  or redemptions from your account if you do not:

- -    provide us with your correct taxpayer identification number;

- -    certify that the taxpayer identification number is correct; and

- -    confirm that you are not subject to backup withholding.

Similarly,  Vanguard  must withhold from your account if the IRS instructs us to
do so.

FOREIGN  INVESTORS.  The Vanguard funds  generally do
not offer their shares for sale outside of the United States.  Foreign investors
should  be aware  that  U.S.  withholding  and  estate  taxes  may  apply to any
investments in Vanguard funds.

INVALID ADDRESSES. If a dividend or capital gains
distribution   check   mailed  to  your   address  of  record  is   returned  as
undeliverable,  Vanguard will  automatically  reinvest all future  distributions
until you  provide  us with a valid  mailing  address.

TAX  CONSEQUENCES.  This
prospectus provides general tax information only. If you are investing through a
tax-deferred retirement account, such as an IRA, special tax rules apply. Please
consult  your  tax  adviser  for  detailed   information   about  a  fund's  tax
consequences for you.




SHARE PRICE

Each Fund's share price,  called its net asset value, or NAV, is calculated each
business day after the close of regular  trading on the New York Stock  Exchange
(the NAV is not  calculated  on  holidays  or other  days when the  Exchange  is
closed).  Each Fund's NAV is expected to remain at a constant  $1.  Although the
stable share price is not  guaranteed,  the Funds are managed and securities are
purchased to maintain that price.

     The  instruments  held by the  Funds are  valued on the basis of  amortized
cost, which does not take into account unrealized capital gains or losses.

     Newspapers typically list money market fund yields weekly,  separately from
listings  for  other  mutual   funds.   Different   newspapers   use   different
abbreviations  for the Funds,  but the most  common  are  VANGPR,  VANGFDL,  and
VANGTRSY.

<PAGE>

16

FINANCIAL HIGHLIGHTS

The following  financial  highlights  tables are intended to help you understand
each  Fund's  financial  performance  for  the  past  five  years,  and  certain
information reflects financial results for a single Fund share in each case. The
total  returns  in each table  represent  the rate that an  investor  would have
earned or lost each year on an investment in the Fund (assuming  reinvestment of
all  dividend  distributions).  This  information  has  been  derived  from  the
financial   statements  audited  by   PricewaterhouseCoopers   LLP,  independent
accountants,  whose  report--along  with each  Fund's  financial  statements--is
included in the Funds' most recent annual report to  shareholders.  You may have
the annual report sent to you without charge by contacting Vanguard.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                   HOW TO READ THE FINANCIAL HIGHLIGHTS TABLES

This explanation uses the Prime Money Market Fund Investor Shares as an example.
The Fund began  fiscal 1999 with a net asset  value  (price) of $1.00 per share.
During  the year,  the Fund  earned  $0.049  per share  from  investment  income
(interest and dividends).

Shareholders  received  $0.049 per share in the form of dividend  distributions.
The  earnings  ($0.049  per share)  minus the  distributions  ($0.049 per share)
resulted in a share price of $1.00 at the end of the year. For a shareholder who
reinvested the  distributions  in the purchase of more shares,  the total return
from the Fund was 4.97% for the year.

As of November 30, 1999, the Fund had $39.4 billion in net assets. For the year,
its  expense  ratio was 0.33%  ($3.30  per  $1,000 of net  assets),  and its net
investment income amounted to 4.85% of its average net assets.

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                                        VANGUARD PRIME MONEY MARKET FUND
                                                INVESTOR SHARES
                                            YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                           1999        1998        1997        1996        1995
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF YEAR        $1.00       $1.00       $1.00       $1.00       $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income     .049        .053        .053        .052        .057
 Net Realized and
  Unrealized Gain (Loss)
  on Investments             --          --          --          --          --
                        --------------------------------------------------------
   Total from Investment
    Operations             .049        .053        .053        .052        .057
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income       (.049)      (.053)      (.053)      (.052)      (.057)
 Distributions from
  Realized Capital
  Gains                      --          --          --          --          --
                        --------------------------------------------------------
   Total Distributions    (.049)      (.053)      (.053)      (.052)      (.057)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF YEAR                  $1.00       $1.00       $1.00       $1.00       $1.00
================================================================================

TOTAL RETURN              4.97%       5.42%       5.41%       5.31%       5.82%
================================================================================
RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)       $39,430     $33,732     $26,480     $22,218     $18,764
 Ratio of Total
  Expenses to Average
  Net Assets              0.33%       0.33%       0.32%       0.32%       0.32%
 Ratio of Net
  Investment Income to
  Average Net Assets      4.85%       5.28%       5.28%       5.18%       5.64%
================================================================================


<PAGE>

17


- --------------------------------------------------------------------------------
                                    VANGUARD FEDERAL MONEY MARKET FUND
                                         YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                           1999        1998        1997        1996        1995
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF YEAR        $1.00       $1.00       $1.00       $1.00       $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income     .048        .052        .052        .051        .056
 Net Realized and
  Unrealized Gain (Loss)
  on Investments             --          --          --          --          --
                        --------------------------------------------------------
   Total from Investment
    Operations             .048        .052        .052        .051        .056
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income       (.048)      (.052)      (.052)      (.051)      (.056)
 Distributions from
  Realized Capital Gains     --          --          --          --          --
                        --------------------------------------------------------
   Total Distributions    (.048)      (.052)      (.052)      (.051)      (.056)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF YEAR                  $1.00       $1.00       $1.00       $1.00       $1.00
================================================================================

TOTAL RETURN              4.89%       5.35%       5.35%       5.26%       5.77%
================================================================================

RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)        $5,243      $4,263      $3,495      $3,100      $2,637
 Ratio of Total
  Expenses to Average
  Net Assets              0.33%       0.33%       0.32%       0.32%       0.32%
 Ratio of Net
  Investment Income to
  Average Net Assets      4.79%       5.21%       5.22%       5.13%       5.61%
================================================================================

- --------------------------------------------------------------------------------
                                   VANGUARD TREASURY MONEY MARKET FUND
                                         YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                           1999        1998        1997        1996        1995
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF YEAR        $1.00       $1.00       $1.00       $1.00       $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income     .044        .050        .050        .050        .053
 Net Realized and
  Unrealized Gain (Loss)
  on Investments             --          --          --          --          --
                        --------------------------------------------------------
   Total from Investment
    Operations             .044        .050        .050        .050        .053
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income       (.044)      (.050)      (.050)      (.050)      (.053)
 Distributions from
  Realized Capital Gains     --          --          --          --          --
                        --------------------------------------------------------
   Total Distributions    (.044)      (.050)      (.050)      (.050)      (.053)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF YEAR                  $1.00       $1.00       $1.00       $1.00       $1.00
================================================================================

TOTAL RETURN              4.51%       5.06%       5.10%       5.11%       5.47%
================================================================================

RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)        $4,593      $3,942      $3,237      $2,917      $2,527
 Ratio of Total
  Expenses to Average
  Net Assets              0.33%       0.33%       0.32%       0.32%       0.32%
 Ratio of Net
  Investment Income to
  Average Net Assets      4.41%       4.94%       4.98%       4.99%       5.33%
================================================================================


"Standard & Poor's(R),"  "S&P(R),"  "S&P  500(R),"  "Standard & Poor's 500," and
"500" are trademarks of The McGraw-Hill Companies, Inc.

<PAGE>

18

- --------------------------------------------------------------------------------
INVESTING WITH VANGUARD

Are you looking for the most  convenient  way to open or add money to a Vanguard
account?  Obtain instant access to fund information?  Establish an account for a
minor child or for your retirement savings?

     Vanguard  can help.  Our goal is to make it easy and pleasant for you to do
business with us.

     The following  sections of the prospectus briefly explain the many services
we offer.  Booklets providing detailed information are available on the services
marked with a [BOOK]. Please call us to request copies.
- --------------------------------------------------------------------------------


SERVICES AND ACCOUNT FEATURES
Vanguard  offers many services that make it convenient to buy, sell, or exchange
shares, or to obtain fund or account information.
- --------------------------------------------------------------------------------
TELEPHONE REDEMPTIONS (SALES AND EXCHANGES)
Automatically set up for each Fund unless you notify us otherwise.
- --------------------------------------------------------------------------------
CHECKWRITING [CHECK]
Method for drawing money from your account by writing a check for $250 or more.
- --------------------------------------------------------------------------------
VANGUARD(R) DIRECT DEPOSIT SERVICE [BOOK]
Automatic  method  for  depositing  your  paycheck  or U.S.  government  payment
(including Social Security and government pension checks) into your account.
- --------------------------------------------------------------------------------
VANGUARD(R) AUTOMATIC EXCHANGE SERVICE [BOOK]
Automatic  method for  moving a fixed  amount of money  from one  Vanguard  fund
account to another.
- --------------------------------------------------------------------------------
VANGUARD FUND EXPRESS(R) [BOOK]
Electronic  method for buying or selling shares.  You can transfer money between
your  Vanguard  fund account and an account at your bank,  savings and loan,  or
credit union on a systematic schedule or whenever you wish.
- --------------------------------------------------------------------------------
VANGUARD DIVIDEND EXPRESS(TM) [BOOK]
Electronic method for transferring  dividend and/or capital gains  distributions
directly  from your  Vanguard  fund account to your bank,  savings and loan,  or
credit union account.
- --------------------------------------------------------------------------------
VANGUARD TELE-ACCOUNT(R) 1-800-662-6273 (ON-BOARD) [BOOK]

Toll-free  24-hour access to Vanguard fund and account  information--as  well as
some  transactions--by  using any touch-tone phone.  Tele-Account provides total
return,  share price, price change, and yield quotations for all Vanguard funds;
gives your account balances and history (e.g., last transaction, latest dividend
distribution);  and  allows  you to sell or  exchange  shares  to and from  most
Vanguard funds.

- --------------------------------------------------------------------------------
ACCESS VANGUARD(TM) www.vanguard.com [COMPUTER]

You can use your  personal  computer to perform  certain  transactions  for most
Vanguard  funds by accessing our website.  To establish  this service,  you must
register  through our website.  We will then mail you an account access password
that  allows  you  to  process  the  following   financial  and   administrative
transactions  online:

- -    Open a new account.*
- -    Buy, sell, or exchange shares of most funds.
- -    Change your name/address.

<PAGE>

19


- -    Add/change fund options (including dividend options, Vanguard Fund Express,
     bank instructions,  checkwriting, and Vanguard Automatic Exchange Service).
     (Some  restrictions may apply.) Please call our Client Services  Department
     for assistance.

*Only current Vanguard shareholders can open a new account online, by exchanging
 shares from other existing Vanguard accounts.
- --------------------------------------------------------------------------------
INVESTOR INFORMATION DEPARTMENT: 1-800-662-7447 (SHIP) TEXT TELEPHONE:
1-800-952-3335
Call  Vanguard for  information  on our funds,  fund  services,  and  retirement
accounts, and to request literature.
- --------------------------------------------------------------------------------

CLIENT SERVICES DEPARTMENT: 1-800-662-2739 (CREW) TEXT TELEPHONE: 1-800-749-7273

Call Vanguard for information on your account, account transactions, and account
statements.
- --------------------------------------------------------------------------------
SERVICES  FOR  CLIENTS  OF  VANGUARD'S  INSTITUTIONAL  DIVISION:  1-888-809-8102
Vanguard's  Institutional  Division offers a variety of specialized services for
large  institutional   investors,   including  the  ability  to  effect  account
transactions through private electronic networks and third-party recordkeepers.
- --------------------------------------------------------------------------------


TYPES OF ACCOUNTS

Individuals and institutions can establish a variety of accounts with Vanguard.
- --------------------------------------------------------------------------------
FOR ONE OR MORE PEOPLE
Open an account in the name of one (individual) or more (joint tenants) people.
- --------------------------------------------------------------------------------
FOR HOLDING PERSONAL TRUST ASSETS [BOOK]
Invest assets held in an existing personal trust.
- --------------------------------------------------------------------------------
FOR INDIVIDUAL RETIREMENT ACCOUNTS [BOOK]
Open a  traditional  IRA account or a Roth IRA  account.  Eligibility  and other
requirements  are  established  by federal law and  Vanguard  custodial  account
agreements. For more information, please call 1-800-662-7447 (SHIP).
- --------------------------------------------------------------------------------
FOR AN ORGANIZATION [BOOK]
Open an account as a corporation,  partnership,  endowment, foundation, or other
entity.
- --------------------------------------------------------------------------------
FOR THIRD-PARTY TRUSTEE RETIREMENT INVESTMENTS
Open an account as a retirement trust or plan based on an existing  corporate or
institutional  plan.  These  accounts  are  established  by the  trustee  of the
existing plan.
- --------------------------------------------------------------------------------
VANGUARD PROTOTYPE PLANS
Open a  variety  of  retirement  accounts  using  Vanguard  prototype  plans for
individuals,  sole proprietorships,  and small businesses. For more information,
please call 1-800-662-2003.
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
A NOTE ON INVESTING WITH VANGUARD THROUGH OTHER FIRMS
You may purchase or sell Fund shares through a financial  intermediary such as a
bank,  broker,  or investment  adviser.  If you invest with Vanguard  through an
intermediary,  please read that firm's program  materials  carefully to learn of
any  special  rules  that may apply.  For  example,  special  terms may apply to
additional service features, fees, or other policies.  Consult your intermediary
to determine when your order will be priced.
- --------------------------------------------------------------------------------

<PAGE>

20

BUYING SHARES

You buy your shares at the Fund's  next-determined share price (net asset value)
after Vanguard receives your request,  which should be $1 per share. Before your
contribution  to a money  market fund can be  invested,  it must be converted to
"federal  funds,"  which  are  Federal  Reserve  deposits  that  banks and other
financial  institutions  draw upon to meet short-term cash needs--and which fund
advisers must use to pay for the  securities  they buy.  Vanguard  converts your
money market investment to federal funds,  which usually takes one business day.
Because of this conversion period, your money market account will be credited on
the business day following the day your  investment is received.  You will begin
earning  dividends on your investment on the next calendar day. For example,  if
your check is received on a Thursday before the close of trading on the New York
Stock Exchange, your account will be credited the next business day (Friday) and
you will begin earning dividends on Saturday.

     Each of the Funds is offered on a no-load  basis,  meaning  that you do not
pay sales commissions or 12b-1 distribution fees.
- --------------------------------------------------------------------------------
MINIMUM INVESTMENT TO . . .
open a new account
$3,000 (regular account); $1,000 (traditional IRAs and Roth IRAs).

add to an existing account
$100 by mail or exchange; $1,000 by wire.
- --------------------------------------------------------------------------------
A NOTE ON LOW BALANCES

The Fund  reserves  the  right to close any  nonretirement  fund  account  whose
balance falls below the minimum initial  investment.  The Fund will deduct a $10
annual fee in June if your  nonretirement  account balance at that time is below
$2,500.  The low balance fee is waived for investors who have aggregate Vanguard
account assets of $50,000 or more.

- --------------------------------------------------------------------------------
BY MAIL TO . . . [ENVELOPE]
open a new account

Complete and sign the account registration form and enclose your check.

add to an existing account
Mail your check with an  Invest-By-Mail  form  detached  from your  confirmation
statement to the address listed on the form. Please do not alter  Invest-By-Mail
forms, since they are fund- and account-specific.

Make your check payable to: The Vanguard Group-(insert  appropriate Fund number;
see below)
Vanguard Prime Money Market Fund-30
Vanguard Federal Money Market Fund-33
Vanguard Treasury Money Market Fund-50

All  purchases  must be made in U.S.  dollars,  and checks must be drawn on U.S.
banks.

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 1110                455 Devon Park Drive
Valley Forge, PA 19482-1110  Wayne, PA 19087-1815


<PAGE>

21

For clients of Vanguard's Institutional Division . . .

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 2900                455 Devon Park Drive
Valley Forge, PA 19482-2900  Wayne, PA 19087-1815
- --------------------------------------------------------------------------------
IMPORTANT  NOTE:  To prevent  check fraud,  Vanguard will not accept checks made
payable to third parties.
- --------------------------------------------------------------------------------
BY TELEPHONE TO . . . [TELEPHONE]
open a new account

Call Vanguard  Tele-Account*  24 hours a day--or Client Services during business
hours--to exchange from another Vanguard fund account with the same registration
(name, address,  taxpayer  identification  number, and account type). (Note that
some restrictions apply to index fund accounts.)

add to an existing account

Call Vanguard  Tele-Account*  24 hours a day--or Client Services during business
hours--to exchange from another Vanguard fund account with the same registration
(name, address,  taxpayer  identification  number, and account type). (Note that
some restrictions  apply to index fund accounts.) Use Vanguard Fund Express (see
"Services and Account Features") to transfer assets from your bank account. Call
Client Services before your first use to verify that this option is available.

Vanguard Tele-Account     Client Services
1-800-662-6273            1-800-662-2739

*You must obtain a Personal  Identification Number (PIN) through Tele-Account at
 least seven days before you request your first exchange.
- --------------------------------------------------------------------------------
IMPORTANT  NOTE:  Once  you  have  initiated  a  telephone   transaction  and  a
confirmation  number has been assigned,  the transaction  cannot be revoked.  We
reserve the right to refuse any purchase request.

- --------------------------------------------------------------------------------
BY WIRE TO OPEN A NEW ACCOUNT OR ADD TO AN EXISTING ACCOUNT [WIRE]

Call Client  Services to arrange your wire  transaction.  Wire  transactions  to
retirement  accounts are only  available for asset  transfers and rollovers from
other financial institutions.  Individual IRA contributions will not be accepted
by wire.

Wire to:
FRB ABA 021001088
HSBC Bank USA

For credit to:
Account: 000112046
Vanguard Incoming Wire Account

In favor of:
Vanguard Prime Money Market Fund-30
Vanguard Federal Money Market Fund-33
Vanguard Treasury Money Market Fund-50
[Account number, or temporary number for a new account]
[Registered account owner(s)]
[Registered address]

<PAGE>

22

If you buy fund shares  through a federal  funds wire,  your  investment  begins
earning  dividends  the next  calendar  day.  You can  begin  earning  dividends
immediately if you notify Vanguard by 10:45 a.m. Eastern time that you intend to
make a wire purchase that day.
- --------------------------------------------------------------------------------
You can redeem (that is, sell or exchange) shares purchased by check or Vanguard
Fund  Express  at any time.  However,  while  your  redemption  request  will be
processed  at the  next-determined  net asset value after it is  received,  your
redemption  proceeds  will not be available  until  payment for your purchase is
collected, which may take up to ten calendar days.
- --------------------------------------------------------------------------------
A NOTE ON LARGE PURCHASES

It is important that you call Vanguard  before you invest a large dollar amount.
It is our responsibility to consider the interests of all Fund shareholders, and
so we  reserve  the right to refuse any  purchase  that may  disrupt  the Fund's
operation or performance.

- --------------------------------------------------------------------------------


REDEEMING SHARES

This section  describes how you can redeem--that is, sell or exchange--a  Fund's
shares.

When Selling Shares:
- -    Vanguard sends the redemption proceeds to you or a designated third party.*
- -    You can sell all or part of your Fund shares at any time.

*May require a signature guarantee; see footnote on page 23.

When Exchanging Shares:
- -    The redemption proceeds are used to purchase shares of a different Vanguard
     fund.
- -    You must meet the receiving fund's minimum investment requirements.
- -    Vanguard reserves the right to revise or terminate the exchange  privilege,
     limit the amount of an exchange, or reject an exchange at any time, without
     notice.

- -    In  order  to  exchange  into  an  account  with a  different  registration
     (including a different name, address, or taxpayer  identification  number),
     you must include the guaranteed signatures of all current account owners on
     your written instructions.

In both  cases,  your  transaction  will be based on the Fund's  next-determined
share price, subject to any special rules discussed in this prospectus.
- --------------------------------------------------------------------------------
NOTE:  Once a redemption  is initiated  and a  confirmation  number  given,  the
transaction CANNOT be canceled.

- --------------------------------------------------------------------------------

HOW TO REQUEST A REDEMPTION
You can request a  redemption  from your Fund  account in any one of three ways:
online, by telephone, or by mail. You can also sell shares by check.

     The Vanguard funds whose shares you cannot  exchange online or by telephone
are VANGUARD U.S.  STOCK INDEX FUNDS,  VANGUARD  BALANCED  INDEX FUND,  VANGUARD
INTERNATIONAL  STOCK INDEX FUNDS,  VANGUARD REIT INDEX FUND, and VANGUARD GROWTH
AND INCOME FUND. These funds do, however,  permit online and telephone exchanges
within  IRAs and some other  retirement  accounts.  If you sell  shares of these
funds online, a redemption check will be sent to your address of record.

- --------------------------------------------------------------------------------

<PAGE>

23

- --------------------------------------------------------------------------------
ONLINE REQUESTS [COMPUTER]
ACCESS VANGUARD at www.vanguard.com

You can use your personal  computer to sell or exchange  shares of most Vanguard
funds by accessing our website.  To establish  this  service,  you must register
through our website.  We will then mail you an account access password that will
enable  you to sell  or  exchange  shares  online  (as  well  as  perform  other
transactions).

- --------------------------------------------------------------------------------
TELEPHONE REQUESTS [TELEPHONE]
All Account Types Except Retirement:
Call Vanguard  Tele-Account  24 hours a day--or Client  Services during business
hours--to sell or exchange  shares.  You can exchange shares from a Fund to open
an account in  another  Vanguard  fund or to add to an  existing  Vanguard  fund
account with an identical registration.

Retirement Accounts:
You can  exchange--but  not  sell--shares  by  calling  Tele-Account  or  Client
Services.

Vanguard Tele-Account     Client Services
1-800-662-6273            1-800-662-2739
- --------------------------------------------------------------------------------
SPECIAL  INFORMATION:  We will automatically  establish the telephone redemption
option for your  account,  unless you instruct us  otherwise  in writing.  While
telephone  redemption is easy and convenient,  this account  feature  involves a
risk of loss from  unauthorized or fraudulent  transactions.  Vanguard will take
reasonable  precautions  to protect your  account from fraud.  You should do the
same by keeping your account information  private and immediately  reviewing any
account  statements  that  we  send  to  you.  Make  sure  to  contact  Vanguard
immediately about any transaction you believe to be unauthorized.
- --------------------------------------------------------------------------------
We reserve the right to refuse a telephone redemption if the caller is unable to
provide:
- -    The ten-digit account number.
- -    The name and address exactly as registered on the account.
- -    The primary Social Security or employer identification number as registered
     on the account.

- -    The  Personal   Identification   Number,   if  applicable   (for  instance,
     Tele-Account).

     Please note that Vanguard will not be  responsible  for any account  losses
due to telephone  fraud, so long as we have taken reasonable steps to verify the
caller's identity.  If you wish to remove the telephone  redemption feature from
your account, please notify us in writing.
- --------------------------------------------------------------------------------
A NOTE ON  UNUSUAL  CIRCUMSTANCES
Vanguard  reserves the right to revise or  terminate  the  telephone  redemption
privilege at any time,  without notice.  In addition,  Vanguard can stop selling
shares or postpone  payment at times when the New York Stock  Exchange is closed
or under any emergency  circumstances  as determined by the U.S.  Securities and
Exchange Commission.  If you experience difficulty making a telephone redemption
during  periods  of  drastic  economic  or market  change,  you can send us your
request  by  regular or express  mail.  Follow  the  instructions  on selling or
exchanging shares by mail in this section.
- --------------------------------------------------------------------------------
MAIL REQUESTS [ENVELOPE]
All Account Types Except Retirement:
Send a letter of instruction signed by all registered  account holders.  Include
the fund name and  account  number and (if you are  selling) a dollar  amount or
number  of shares  OR (if you are  exchanging)  the name of the fund you want to
exchange into and a dollar amount or

<PAGE>

24

number of shares.  To exchange  into an account  with a  different  registration
(including a different name, address, taxpayer identification number, or account
type),  you must provide  Vanguard  with written  instructions  that include the
guaranteed  signatures of all current  owners of the fund from which you wish to
redeem.

Vanguard Retirement Accounts:
For information on how to request distributions from:
- -    Traditional IRAs and Roth IRAs--call Client Services.
- -    SEP-IRAs, SIMPLE IRAs, 403(b)(7) custodial accounts, and Profit-Sharing and
     Money Purchase Pension (Keogh) Plans--call  Individual  Retirement Plans at
     1-800-662-2003.

Depending on your account  registration  type,  additional  documentation may be
required.

First-class mail to:         Express or Registered mail to:

The Vanguard Group           The Vanguard Group
P.O. Box 1110                455 Devon Park Drive
Valley Forge, PA 19482-1110  Wayne, PA 19087-1815

For clients of Vanguard's Institutional Division . . .

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 2900                455 Devon Park Drive
Valley Forge, PA 19482-2900  Wayne, PA 19087-1815
- --------------------------------------------------------------------------------
CHECK REQUESTS [CHECK]
You can sell shares by writing a check for $250 or more.
- --------------------------------------------------------------------------------
A NOTE ON LARGE REDEMPTIONS

It is important that you call Vanguard  before you redeem a large dollar amount.
It is our  responsibility to consider the interests of all fund shareholders and
so we reserve the right to delay  delivery of your  redemption  proceeds--up  to
seven days--if the amount may disrupt the Fund's operation or performance.
     If you redeem more than  $250,000  worth of Fund  shares  within any 90-day
period,  the  Fund  reserves  the  right  to pay  part or all of the  redemption
proceeds above $250,000  in-kind,  i.e., in securities,  rather than in cash. If
payment is made in-kind,  you may incur  brokerage  commissions  if you elect to
sell the securities for cash.

- --------------------------------------------------------------------------------

OPTIONS FOR REDEMPTION PROCEEDS

You may receive your redemption proceeds in one of four ways: check, wire (money
market funds and other daily dividend funds only),  exchange to another Vanguard
fund, or Fund Express Redemption.

- --------------------------------------------------------------------------------
CHECK REDEMPTIONS
Normally,  Vanguard  will  mail  your  check  within  two  business  days  of  a
redemption.
- --------------------------------------------------------------------------------
WIRE REDEMPTIONS [WIRE]
The wire redemption option is not automatic; you must establish it by completing
a special  form or the  appropriate  section of your account  application.  Wire
redemptions can be initiated by mail or by telephone during Vanguard's  business
hours, but not online.

<PAGE>

25

For Money Market Funds:

For telephone  requests made by 10:30 a.m. Eastern time, the wire will arrive at
your  bank by the close of  business  that  same  day.  Requests  made by 4 p.m.
Eastern time will arrive at your bank by the close of business on the  following
business day.

For Other Daily Dividend Funds:
For telephone requests made by 4 p.m. Eastern time, the wire will arrive at your
bank by the close of business on the following business day.

- --------------------------------------------------------------------------------
NOTE: Wire redemptions of less than $5,000 are subject to a $5 processing fee.
- --------------------------------------------------------------------------------
EXCHANGE REDEMPTIONS
As described  above, an exchange  involves using the proceeds of your redemption
to purchase shares of another Vanguard fund.
- --------------------------------------------------------------------------------

FUND EXPRESS REDEMPTIONS
Vanguard  will  electronically  transfer  funds to your  pre-linked  checking or
savings account.

- --------------------------------------------------------------------------------
FOR OUR MUTUAL PROTECTION
For your best interests and ours, Vanguard applies these additional requirements
to redemptions:

REQUEST IN "GOOD ORDER"
All redemption requests must be received by Vanguard in "good order." This means
that your request must include:
- -    The Fund name and account number.
- -    The amount of the transaction (in dollars or shares).
- -    Signatures  of all owners  exactly as  registered  on the account (for mail
     requests).
- -    Signature guarantees (if required).*
- -    Any supporting legal documentation that may be required.
- -    Any outstanding certificates representing shares to be redeemed.

*For instance,  a signature guarantee must be provided by all registered account
 shareholders  when redemption  proceeds are to be sent to a different person or
 address. A signature guarantee can be obtained from most commercial and savings
 banks,  credit  unions,  trust  companies,  or  member  firms  of a U.S.  stock
 exchange.

TRANSACTIONS ARE PROCESSED AT THE NEXT-DETERMINED SHARE PRICE AFTER VANGUARD HAS
RECEIVED ALL REQUIRED INFORMATION.
- --------------------------------------------------------------------------------
RETURN YOUR SHARE CERTIFICATES
Any portion of your account represented by share certificates cannot be redeemed
until you return the  certificates  to Vanguard.  Certificates  must be returned
(unsigned),  along with a letter  requesting  the sale or  exchange  you wish to
process, via certified mail to:

The Vanguard Group
455 Devon Park Drive
Wayne, PA 19087-1815
- --------------------------------------------------------------------------------

ALL TRADES ARE FINAL
Vanguard  will not cancel any  transaction  request  (including  any purchase or
redemption)  that we believe to be authentic once the request has been initiated
and a confirmation number assigned.

- --------------------------------------------------------------------------------

<PAGE>

26

- --------------------------------------------------------------------------------

UNCASHED CHECKS
Please cash your distribution or redemption  checks promptly.  Vanguard will not
pay interest on uncashed checks.

- --------------------------------------------------------------------------------


TRANSFERRING REGISTRATION

You can  transfer  the  registration  of your Fund  shares to  another  owner by
completing a transfer form and sending it to Vanguard.

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 1110                455 Devon Park Drive
Valley Forge, PA 19482-1110  Wayne, PA 19087-1815

For clients of Vanguard's Institutional Division . . .

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 2900                455 Devon Park Drive
Valley Forge, PA 19482-2900  Wayne, PA 19087-1815
- --------------------------------------------------------------------------------


FUND AND ACCOUNT UPDATES

STATEMENTS AND REPORTS
We will send you account and tax  statements to help you keep track of your Fund
account  throughout  the year as well as when you are preparing  your income tax
returns.

 In addition,  you will receive  financial reports about your Fund twice a year.
These comprehensive reports include an assessment of the Fund's performance (and
a comparison to its industry benchmark), an overview of the financial markets, a
report from the adviser,  and the Fund's  financial  statements  which include a
listing of the Fund's holdings.
     To keep  each  Fund's  costs as low as  possible  (so  that  you and  other
shareholders can keep more of the Fund's investment earnings), Vanguard attempts
to  eliminate  duplicate  mailings  to the same  address.  When two or more Fund
shareholders  have the same last name and address,  we send just one Fund report
to that address--instead of mailing separate reports to each shareholder. If you
want us to send  separate  reports,  notify our Client  Services  Department  at
1-800-662-2739.

- --------------------------------------------------------------------------------
CONFIRMATION STATEMENT
Sent each time you buy,  sell, or exchange  shares;  confirms the trade date and
the amount of your transaction.
- --------------------------------------------------------------------------------
PORTFOLIO SUMMARY [BOOK]
Mailed  quarterly for most  accounts;  shows the market value of your account at
the close of the statement period, as well as distributions,  purchases,  sales,
and exchanges for the current calendar year.
- --------------------------------------------------------------------------------
FUND FINANCIAL REPORTS
Mailed in January and July for these Funds.
- --------------------------------------------------------------------------------

<PAGE>

27

- --------------------------------------------------------------------------------
TAX STATEMENTS
Generally  mailed in January;  report previous  year's  dividend  distributions,
proceeds  from  the  sale of  shares,  and  distributions  from  IRAs  or  other
retirement accounts.
- --------------------------------------------------------------------------------
CHECKWRITING STATEMENT
Sent monthly to shareholders using Vanguard's checkwriting option. Our statement
provides  images of the front and back of each  checkwriting  draft  paid in the
previous  month.  This  consolidated  statement  is sent instead of the original
canceled drafts, which will not be returned.
- --------------------------------------------------------------------------------

<PAGE>


                     (THIS PAGE INTENTIONALLY LEFT BLANK.)

<PAGE>

GLOSSARY OF INVESTMENT TERMS

DIVIDEND INCOME
Payment to  shareholders  of income from  interest or  dividends  generated by a
fund's investments.

EXPENSE RATIO
The  percentage  of a fund's  average net assets used to pay its  expenses.  The
expense ratio  includes  management  fees,  administrative  fees,  and any 12b-1
distribution fees.

INVESTMENT ADVISER
An  organization  that  makes  the  day-to-day   decisions  regarding  a  fund's
investments.

LIQUIDITY
The degree of a security's  marketability (that is, how quickly the security can
be sold at a fair price and converted to cash).

MONEY MARKET FUND
A mutual fund that seeks to provide income,  liquidity, and a stable share price
by investing in very short-term, liquid investments.

MONEY MARKET INSTRUMENTS
Short-term,  liquid  investments (usually with a maturity of 13 months or less),
which  include  U.S.   Treasury  bills,  bank  certificates  of  deposit  (CDs),
repurchase agreements, commercial paper, and banker's acceptances.

MUTUAL FUND
An  investment  company  that pools the money of many people and invests it in a
variety of securities in an effort to achieve a specific objective over time.

NET ASSET VALUE (NAV)
The market value of a mutual fund's total assets, minus liabilities,  divided by
the  number of shares  outstanding.  The value of a single  share is called  its
share value or share price.

PRINCIPAL
The amount of money you put into an investment.

SECURITIES
Stocks,  bonds,  money market  instruments,  and  interests in other  investment
vehicles.

TOTAL RETURN
A percentage change,  over a specified time period, in a mutual fund's net asset
value,  with the ending net asset value adjusted to account for the reinvestment
of all distributions of dividends and capital gains.

VOLATILITY
The  fluctuations  in value of a mutual  fund or other  security.  The greater a
fund's volatility, the wider the fluctuations between its high and low prices.

YIELD
Income  (interest  or  dividends)  earned  by  an  investment,  expressed  as  a
percentage of the investment's price.

<PAGE>


                                                    [SHIP(R) LOGO]
                                                    [THE VANGUARD GROUP(R) LOGO]

                                                    Post Office Box 2600
                                                    Valley Forge, PA 19482-2600

FOR MORE INFORMATION
If you'd like more information about
Vanguard Money Market Funds, the
following documents are available
free upon request:

ANNUAL/SEMIANNUAL REPORT
TO SHAREHOLDERS
Additional information about the
Funds' investments is available in
the Funds' annual and semiannual
reports to shareholders.

STATEMENT OF ADDITIONAL
INFORMATION (SAI)
The SAI provides more detailed
information about the Funds.

The current annual and semiannual
reports and the SAI are
incorporated by reference into
(and are thus legally a part of)
this prospectus.

To receive a free copy of the latest
annual or semiannual report or the
SAI, or to request additional
information about the Funds or other
Vanguard funds, please contact us
as follows:

THE VANGUARD GROUP
INVESTOR INFORMATION DEPARTMENT
P.O. BOX 2600
VALLEY FORGE, PA 19482-2600

TELEPHONE:
1-800-662-7447 (SHIP)

TEXT TELEPHONE:
1-800-952-3335

WORLD WIDE WEB:
WWW.VANGUARD.COM

If you are a current Fund shareholder
and would like information about
your account, account transactions,
and/or account statements,
please call:

CLIENT SERVICES DEPARTMENT
TELEPHONE:
1-800-662-2739 (CREW)

TEXT TELEPHONE:
1-800-749-7273

INFORMATION PROVIDED BY THE
SECURITIES AND EXCHANGE
COMMISSION (SEC)
You can review and copy
information about the Funds
(including the SAI) at the SEC's
Public Reference Room in
Washington, DC. To find out more
about this public service, call the
SEC at 1-800-SEC-0330. Reports and
other information about the Funds
are also available on the SEC's
website (www.sec.gov), or you can
receive copies of this information,
for a fee, by writing the Public
Reference Section, Securities and
Exchange Commission, Washington,
DC 20549-0102.

Vanguard Prime and Federal Money
Market Funds' Investment Company
Act file number: 811-2554

Vanguard Treasury Money Market
Fund's Investment Company Act file
number: 811-7803

(C) 2000 The Vanguard Group, Inc.
All rights reserved.
Vanguard Marketing Corporation,
Distributor.

P030N-03/24/2000


<PAGE>

                                                          VANGUARD(R)
                                                          MONEY MARKET
                                                          FUNDS

                                                          Participant Prospectus
                                                          March 24, 2000

This  prospectus  contains
financial data for the
Funds through the
fiscal year ended
November 30, 1999.

VANGUARD PRIME
MONEY MARKET FUND

VANGUARD FEDERAL
MONEY MARKET FUND

VANGUARD TREASURY
MONEY MARKET FUND

                                                        [MEMBERS OF
                                                        THE VANGUARD GROUP LOGO]
<PAGE>

VANGUARD MONEY MARKET FUNDS

Participant Prospectus

March 24, 2000




- --------------------------------------------------------------------------------
   CONTENTS
- --------------------------------------------------------------------------------

 1 FUND PROFILES                            14 DIVIDENDS AND TAXES

   1 Vanguard Prime Money Market Fund       14 SHARE PRICE

   4 Vanguard Federal Money Market Fund     15 FINANCIAL HIGHLIGHTS

   7 Vanguard Treasury Money Market Fund    17 INVESTING WITH VANGUARD

10 MORE ON THE FUNDS                        17 ACCESSING FUND INFORMATION BY
                                               COMPUTER

13 THE FUNDS AND VANGUARD                   GLOSSARY (inside back cover)

13 INVESTMENT ADVISER

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
WHY READING THIS PROSPECTUS IS IMPORTANT

This prospectus  explains the objective,  risks,  and policies of Vanguard Prime
Money Market Fund,  Vanguard  Federal Money Market Fund,  and Vanguard  Treasury
Money Market  Fund.  To  highlight  terms and concepts  important to mutual fund
investors,  we have provided "Plain Talk(R)" explanations along the way. Reading
the  prospectus  will  help you to  decide  which  Fund,  if any,  is the  right
investment for you. We suggest that you keep it for future reference.

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
IMPORTANT NOTE

The Prime Money Market Fund offers two separate classes of shares:  Investor and
Institutional. This prospectus offers the Fund's Investor Shares to participants
in  employer-sponsored  retirement  or savings  plans.  Please call  Vanguard to
obtain separate prospectuses that offer:
- -    Investor Shares for private investors ($3,000 minimum)--1-800-662-7447
- -    Institutional    Shares   for   very   large    investors    ($10   million
     minimum)--1-800-523-1036
     The Fund's  separate  share classes have different  expenses;  as a result,
their investment  performances will vary. UNLESS OTHERWISE NOTED, ALL REFERENCES
IN  THIS  PROSPECTUS  TO  FEES,  EXPENSES,  AND  INVESTMENT  PERFORMANCE  RELATE
SPECIFICALLY TO INVESTOR SHARES.

- --------------------------------------------------------------------------------


NEITHER  THE  SECURITIES  AND  EXCHANGE  COMMISSION  NOR  ANY  STATE  SECURITIES
COMMISSION HAS APPROVED OR  DISAPPROVED  OF THESE  SECURITIES OR PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

<PAGE>

1

FUND PROFILE--
VANGUARD PRIME MONEY MARKET FUND

The following  profile  summarizes  key features of Vanguard  Prime Money Market
Fund.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests primarily in high-quality, short-term money market instruments,
including certificates of deposit,  banker's acceptances,  commercial paper, and
other  money  market  securities.  To be  considered  high  quality,  a security
generally must be rated in one of the two highest credit-quality  categories for
short-term  securities by at least two nationally recognized rating services (or
by one, if only one rating  service  has rated the  security).  If unrated,  the
security must be determined by the Fund's adviser to be of quality equivalent to
those in the two highest  credit-quality  categories.  The Fund will maintain an
average  maturity  of 90 days or  less.  For  more  information,  see  "Security
Selection" under MORE ON THE FUNDS.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential to hurt the Fund's performance, should be low for the Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION

The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.


<PAGE>

2


              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------

                              1990           8.27%
                              1991           6.14%
                              1992           3.74%
                              1993           3.01%
                              1994           4.08%
                              1995           5.82%
                              1996           5.29%
                              1997           5.44%
                              1998           5.38%
                              1999           5.01%
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 2.03%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.72% (quarter ended June 30, 1993).

        -----------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
        -----------------------------------------------------------------
                                           1 YEAR    5 YEARS   10 YEARS
        -----------------------------------------------------------------
        Vanguard Prime Money Market Fund    5.01%     5.39%      5.21%
        Salomon Smith Barney 3-Month
         Treasury Index                     4.74      5.20       5.05
        Lipper Money Market Fund Average*   4.49      4.88       4.73
        -----------------------------------------------------------------
        *Derived from data provided by Lipper Inc.
        -----------------------------------------------------------------

     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.11%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.22%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.33%


<PAGE>

3

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS    5 YEARS      10 YEARS
- -------------------------------------------------
    $34        $106       $185          $418
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                              NEWSPAPER ABBREVIATION
Declared daily and distributed on the  VangPr
first business day of each month
                                       VANGUARD FUND NUMBER
INVESTMENT ADVISER                     030
The Vanguard Group, Valley Forge,
Pa., since 1981                        CUSIP NUMBER
                                       922906201
INCEPTION DATE
June 4, 1975                           TICKER SYMBOL
                                       VMMXX
NET ASSETS AS OF NOVEMBER 30, 1999
$41.2 billion

- --------------------------------------------------------------------------------

<PAGE>

4

FUND PROFILE--
VANGUARD FEDERAL MONEY MARKET FUND

The following  profile  summarizes key features of Vanguard Federal Money Market
Fund.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests primarily in high-quality,  short-term money market instruments
issued by U.S. government agencies.  Most of the securities held by the Fund are
not backed by the full faith and  credit of the U.S.  government.  The Fund will
maintain  an average  maturity  of 90 days or less.  For more  information,  see
"Security Selection" under MORE ON THE FUNDS.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential to hurt the Fund's performance, should be very low for the Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION

The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.



<PAGE>

5


              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------
                              1990           8.07%
                              1991           5.96%
                              1992           3.68%
                              1993           2.98%
                              1994           4.03%
                              1995           5.77%
                              1996           5.24%
                              1997           5.38%
                              1998           5.31%
                              1999           4.94%
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 1.99%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.72% (quarter ended June 30, 1993).

        -----------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
        -----------------------------------------------------------------
                                              1 YEAR  5 YEARS   10 YEARS
        -----------------------------------------------------------------
        Vanguard Federal Money Market Fund     4.94%   5.33%      5.13%
        Salomon Smith Barney 3-Month
         Treasury Index                        4.74    5.20       5.05
        Lipper U.S. Government Money Market
         Fund Average*                         4.47    4.85       4.68
        -----------------------------------------------------------------
        *Derived from data provided by Lipper Inc.
        -----------------------------------------------------------------


     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.13%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.20%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.33%


<PAGE>

6

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS    5 YEARS      10 YEARS
- -------------------------------------------------
    $34        $106       $185          $418
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                              NEWSPAPER ABBREVIATION
Declared daily and distributed on the  VangFdl
first business day of each month
                                       VANGUARD FUND NUMBER
INVESTMENT ADVISER                     033
The Vanguard Group, Valley Forge,
Pa., since inception                   CUSIP NUMBER
                                       922906300
INCEPTION DATE
July 13, 1981                          TICKER SYMBOL
                                       VMFXX
NET ASSETS AS OF NOVEMBER 30, 1999
$5.2 billion

- --------------------------------------------------------------------------------

<PAGE>

7

FUND PROFILE--
VANGUARD TREASURY MONEY MARKET FUND

The following profile  summarizes key features of Vanguard Treasury Money Market
Fund.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests  solely in  high-quality,  short-term  money market  securities
whose interest and principal payments are backed by the full faith and credit of
the U.S.  government.  At least 80% of the Fund's assets will always be invested
in U.S. Treasury securities;  the remainder of the Fund's assets may be invested
in securities issued by U.S. government agencies or instrumentalities.  The Fund
will maintain an average maturity of 90 days or less. For more information,  see
"Security Selection" under MORE ON THE FUNDS.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential  to hurt the Fund's  performance,  should be  negligible  for the
     Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION


The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.


<PAGE>

8


              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------
                              1990           7.94%
                              1991           5.73%
                              1992           3.53%
                              1993           2.86%
                              1994           3.81%
                              1995           5.49%
                              1996           5.09%
                              1997           5.12%
                              1998           5.00%
                              1999           4.55%
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 1.96%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.69% (quarter ended June 30, 1993).

      --------------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
      --------------------------------------------------------------------
                                               1 YEAR  5 YEARS   10 YEARS
      --------------------------------------------------------------------
      Vanguard Treasury Money Market Fund       4.55%   5.05%      4.90%
      Salomon Smith Barney 3-Month
         Treasury Index                         4.74    5.20       5.05
      Lipper U.S. Treasury Money Market Fund
       Average*                                 4.23    4.74       4.64
      --------------------------------------------------------------------
      *Derived from data provided by Lipper Inc.
      --------------------------------------------------------------------

     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.14%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.19%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.33%


<PAGE>

9

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS    5 YEARS      10 YEARS
- -------------------------------------------------
    $34        $106       $185         $418
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                              NEWSPAPER ABBREVIATION
Declared daily and distributed on the  VangTrsy
first business day of each month
                                       VANGUARD FUND NUMBER
INVESTMENT ADVISER                     050
The Vanguard Group, Valley Forge,
Pa., since inception                   CUSIP NUMBER
                                       921948105
INCEPTION DATE
March 9, 1983                          TICKER SYMBOL
                                       VMPXX
NET ASSETS AS OF NOVEMBER 30, 1999
$4.6 billion

- --------------------------------------------------------------------------------

<PAGE>

10

MORE ON THE FUNDS

The following  sections  discuss other important  features of the Vanguard Money
Market Funds,  including  market  exposure,  security  selection,  and costs and
market-timing.  You will also find  detailed  risk  information  about the Funds
throughout these sections.

MARKET EXPOSURE

Each  Fund's  primary  policy  is to invest in very  high-quality  money  market
instruments--also  known as cash reserves--that are considered  short-term (that
is,  they  mature  in 13 months or less).  Each Fund will  maintain  an  average
maturity of 90 days or less.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                            MONEY MARKET INSTRUMENTS

The term "money market  instruments"  refers to a variety of  short-term  liquid
investments,  usually  with a maturity of 13 months or less.  Some common  types
are:  Treasury  bills  and  notes,  which  are  securities  issued  by the  U.S.
government;  commercial  paper,  which  are  promissory  notes  issued  by large
companies or financial firms; banker's acceptances, which are credit instruments
guaranteed by a bank; and negotiable  certificates of deposit,  which are issued
by  banks in  large  denominations.  Money  market  securities  can pay a fixed,
variable, or floating rate of interest.
- --------------------------------------------------------------------------------

[FLAG] EACH FUND IS SUBJECT TO INCOME  RISK,  WHICH IS THE CHANCE  THAT A FUND'S
     DIVIDENDS (THAT IS, INCOME) WILL DECLINE BECAUSE OF FALLING INTEREST RATES.
     BECAUSE THE FUNDS' INCOME IS BASED ON SHORT-TERM INTEREST  RATES--WHICH CAN
     FLUCTUATE  SIGNIFICANTLY OVER SHORT  PERIODS--INCOME RISK IS EXPECTED TO BE
     HIGH FOR ALL THREE FUNDS.




SECURITY SELECTION

The Vanguard  Group,  adviser to the Funds,  selects  high-quality  money market
instruments.  Each Fund focuses on  securities  of a particular  class of issuer
(the U.S. government,  U.S. government agencies, or non-government issuers). The
Funds are managed without regard to tax ramifications.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                 CREDIT QUALITY

A money market  instrument's credit quality depends upon the issuer's ability to
pay interest on the security and,  ultimately,  to repay the debt. The lower the
rating by one of the independent  bond-rating agencies (for example,  Moody's or
Standard & Poor's),  the greater the chance (in the rating agency's opinion) the
security's issuer will default, or fail to meet its payment obligations.  Direct
U.S. Treasury  obligations  (that is, securities issued by the U.S.  government)
carry  the  highest  credit  ratings.  All  things  being  equal,  money  market
instruments with greater credit risk offer higher yields.
- --------------------------------------------------------------------------------

[FLAG] EACH FUND IS  SUBJECT  TO  MANAGER  RISK,  WHICH IS THE  CHANCE  THAT THE
     ADVISER MAY DO A POOR JOB OF SELECTING SECURITIES.


<PAGE>

11

     The Prime Money Market Fund invests  primarily in  certificates of deposit,
banker's  acceptances,  commercial  paper,  and other money  market  securities.
Commercial  paper must be rated Prime-1 by Moody's  Investors  Service or A-1 by
Standard & Poor's  Corporation.  Securities that are unrated must be issued by a
company  with a debt  rating  of A3 or  better  by  Moody's  or A- or  better by
Standard & Poor's.  The Prime  Money  Market  Fund also  invests  in  short-term
corporate,  state, and municipal obligations rated A3 or better by Moody's or A-
or better by Standard & Poor's,  and in securities that are considered  suitable
for the Federal Money Market Fund (see below).

     Among the certificates of deposit  typically held by the Prime Money Market
Fund are Eurodollar and Yankee obligations,  which are primarily certificates of
deposit  issued in U.S.  dollars by foreign  banks and foreign  branches of U.S.
banks. Eurodollar and Yankee obligations have risks similar to U.S. money market
instruments,  such as income risk and credit risk. Other risks of Eurodollar and
Yankee obligations include the possibilities that: a foreign government will not
let U.S.  dollar-denominated  assets  leave the  country;  the banks  that issue
Eurodollar obligations may not be subject to the same regulations as U.S. banks;
and adverse  political or economic  developments  will affect  investments  in a
foreign  country.  Before  the Fund's  adviser  selects a  Eurodollar  or Yankee
obligation,  however,  the  foreign  issuer  undergoes  the same  credit-quality
analysis and tests of financial strength as an issuer of domestic securities.

     The Federal  Money Market Fund invests  primarily in  securities  issued by
U.S. government agencies whose interest and principal payments are not backed by
the full faith and credit of the U.S. government.  These agencies include, among
others,  the Federal Home Loan Bank, the Federal National Mortgage  Association,
and the  Federal  Home Loan  Mortgage  Corporation.  The Fund also may invest in
securities  issued by the U.S.  Treasury and U.S. government  agencies  that are
backed by the full faith and credit of the U.S. government.

     The Treasury Money Market Fund invests solely in securities  whose interest
and  principal  payments  are  backed by the full  faith and  credit of the U.S.
government.  At least 80% of the Fund's  assets  will always be invested in U.S.
Treasury  securities.  The remainder of the Fund's assets may include securities
issued by U.S.  government  agencies,  such as the Government  National Mortgage
Association, the Small Business Administration, and the Federal Financing Bank.

[FLAG] EACH FUND IS SUBJECT,  TO A LIMITED EXTENT,  TO CREDIT RISK, WHICH IS THE
     CHANCE  THAT  THE  ISSUER  OF A  SECURITY  WILL  FAIL TO PAY  INTEREST  AND
     PRINCIPAL IN A TIMELY MANNER.

     The three Funds differ mainly in terms of credit risk.  In absolute  terms,
each Fund's credit quality is very high.

     In relative  terms,  the  Treasury  Money  Market  Fund,  which  invests in
securities  backed by the full faith and credit of the U.S.  government,  offers
the lowest credit risk--and generally the lowest yield--of the three Funds.

     Not all of the  securities  included in the Federal  Money  Market Fund are
backed by the full faith and credit of the U.S. government, and so the potential
credit risk and yield for the Fund are  somewhat  higher  than for the  Treasury
Money Market Fund.

     While the credit  quality of its  securities is very high,  the Prime Money
Market Fund faces more risk because it invests in money market securities issued
by private  companies.  It is possible  that one or more of these  companies may
experience financial  difficulties and, as a result, may fail to pay interest to
the Fund or return the Fund's  principal when repayment

<PAGE>

12

is due.  Therefore,  the Prime Money Market Fund offers the highest credit risk,
and generally the highest yield, of the three Funds.

     Bear in mind that,  while each Fund  invests in  high-quality  money market
instruments,  the three Funds are not insured or  guaranteed  by the FDIC or any
other agency of the U.S. government.

[FLAG] THE PRIME AND FEDERAL  MONEY MARKET FUNDS  RESERVE THE RIGHT TO INVEST IN
     REPURCHASE AGREEMENTS, WHICH ARE SUBJECT TO SPECIFIC RISKS.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                              REPURCHASE AGREEMENTS

A means  of  investing  money  for a short  period,  repurchase  agreements  are
contracts  in which a  financial  institution  sells  securities  and  agrees to
repurchase  the  securities on a specific date  (normally the next business day)
and at a specific price.

- --------------------------------------------------------------------------------

     Repurchase  agreements carry several risks. For instance,  if the seller is
unable to repurchase the securities as promised,  the Fund may experience a loss
when trying to sell the securities to another person.  Or, if the seller becomes
insolvent, a bankruptcy court may determine that the securities do not belong to
the Fund and order that the  securities  be sold to pay off the seller's  debts.
The Funds' adviser  believes that these risks can be controlled  through careful
security selection and monitoring.

[FLAG]  THE  FUNDS  RESERVE  THE  RIGHT  TO  INVEST,  TO A  LIMITED  EXTENT,  IN
     FLOATING-RATE SECURITIES, WHICH ARE TRADITIONAL TYPES OF DERIVATIVES.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                   DERIVATIVES

A derivative is a financial  contract whose value, or interest rate, is based on
(or "derived"  from) a traditional  security  (such as a stock or bond), a money
market  benchmark  (such  as U.S.  Treasury  bill  rates  or the  Federal  Funds
Effective  Rate),  an asset (such as a commodity  like gold),  or a market index
(such as the S&P 500 Index).
- --------------------------------------------------------------------------------

     A floating-rate  security's interest rate, as the name implies, is not set;
instead, it fluctuates periodically. Generally, the security's yield is based on
a U.S. dollar-based  interest-rate benchmark such as the Federal Funds Rate, the
90-day Treasury bill rate, or the London Interbank  Offered Rate (LIBOR).  These
securities reset their yields on a periodic basis (for example,  daily,  weekly,
or quarterly)  and are closely  correlated  to changes in money market  interest
rates.

     The Funds will not use derivatives for speculative purposes or as leveraged
investments that magnify the risks of an investment.

     In  addition,  each Fund may invest up to 10% of its net assets in illiquid
securities. These are securities that cannot be readily resold or converted into
cash.

COSTS AND MARKET-TIMING

The Vanguard Money Market Funds serve both short- and long-term  investor needs;
however,  other  Vanguard  funds are  intended  for  long-term  investors  only.
Investors  who  engage  in  excessive   in-and-out   trading  activity  generate
additional  costs that are borne by all of a fund's  shareholders.  To  minimize
these costs, Vanguard's stock, bond, and balanced funds

<PAGE>

13

have adopted policies to discourage short-term trading--which includes switching
back and forth from the Vanguard Money Market Funds. Please check other Vanguard
funds'  prospectuses  for specifics on the trading  limitations  of those funds.
Also, all Vanguard funds, including the Money Market Funds, reserve the right to
stop offering shares at any time or to reject specific purchase requests.

     THE  VANGUARD  FUNDS DO NOT  PERMIT  MARKET-TIMING.  DO NOT INVEST IN THESE
FUNDS IF YOU ARE A MARKET-TIMER.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                      VANGUARD'S UNIQUE CORPORATE STRUCTURE

The Vanguard Group is truly a MUTUAL mutual fund company. It is owned jointly by
the funds it oversees and thus  indirectly by the  shareholders  in those funds.
Most other mutual funds are operated by for-profit management companies that may
be owned by one person,  by a group of individuals,  or by investors who own the
management  company's stock. By contrast,  Vanguard  provides its services on an
"at cost"  basis,  and the funds' expense  ratios  reflect only these costs.  No
separate  management  company reaps profits or absorbs losses from operating the
funds.
- --------------------------------------------------------------------------------

THE FUNDS AND VANGUARD

The Funds are members of The Vanguard Group, a family of more than 35 investment
companies  with more than 100 funds holding assets worth more than $520 billion.
All of the  Vanguard  funds  share  in the  expenses  associated  with  business
operations, such as personnel, office space, equipment, and advertising.

     Vanguard  also  provides   marketing   services  to  the  funds.   Although
shareholders do not pay sales commissions or 12b-1  distribution fees, each fund
pays its allocated share of The Vanguard Group's marketing costs.

INVESTMENT ADVISER

The Vanguard Group (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, founded in
1974,  serves as the  Funds'  adviser  through  its Fixed  Income  Group.  As of
November 30, 1999,  Vanguard  served as adviser for about $354 billion in assets
including more than 40 Vanguard funds.  Vanguard manages the Funds on an at-cost
basis, subject to the control of the Trustees and officers of the Funds. For the
fiscal year ended November 30, 1999, the investment  advisory  expenses for each
Fund  represented  an effective  annual rate of 0.01% of each Fund's average net
assets.

     The  adviser  places  all orders  for the  purchase  and sale of the Funds'
securities,  and seeks out the best available price and most favorable execution
for all transactions.


<PAGE>

14

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                               THE FUNDS' ADVISER



The individuals responsible for overseeing the Funds' investments are:

IAN A.  MACKINNON,  Managing  Director of Vanguard and head of Vanguard's  Fixed
Income  Group;  has  worked  in  investment   management  since  1974;   primary
responsibility for Vanguard's  internal  fixed-income  policy and strategy since
1981; B.A., Lafayette College; M.B.A., Pennsylvania State University.

ROBERT F.  AUWAERTER,  Principal  of Vanguard  and Fund  Manager;  has worked in
investment  management since 1978; has managed portfolio investments since 1979;
B.S., University of Pennsylvania; M.B.A., Northwestern University.

JOHN HOLLYER,  Principal of Vanguard and Fund Manager;  has worked in investment
management  since 1987;  has managed  portfolio  investments  since 1989;  B.S.,
University of Pennsylvania.

DAVID  R.  GLOCKE,  Principal  of  Vanguard  and Fund  Manager;  has  worked  in
investment  management since 1991; has managed portfolio investments since 1997;
B.S., University of Wisconsin.

Mr.  Auwaerter,  Mr.  Hollyer,  and Mr.  Glocke manage the Funds on a day-to-day
basis.  Mr.  MacKinnon is  responsible  for setting the Funds' broad  investment
policies and for overseeing the Fund Managers.
- --------------------------------------------------------------------------------

DIVIDENDS AND TAXES

Each Fund distributes to shareholders  virtually all of its net income (interest
less expenses). The Fund's income dividends accrue daily, and are distributed on
the first business day of every month.

     Your dividend  distributions  will be reinvested in additional  Fund shares
and  accumulate  on a  tax-deferred  basis  if  you  are  investing  through  an
employer-sponsored  retirement or savings plan.  You will not owe taxes on these
distributions until you begin withdrawals from the plan. You should consult your
plan  administrator,  your plan's Summary Plan Description,  or your tax adviser
about the tax consequences of plan withdrawals.




SHARE PRICE

Each Fund's share price,  called its net asset value, or NAV, is calculated each
business day after the close of regular  trading on the New York Stock  Exchange
(the NAV is not  calculated  on  holidays  or other  days when the  Exchange  is
closed).  Each Fund's NAV is expected to remain at a constant  $1.  Although the
stable share price is not  guaranteed,  the Funds are managed and securities are
purchased to maintain that price.

     The  instruments  held by the  Funds are  valued on the basis of  amortized
cost, which does not take into account unrealized capital gains or losses.

     Newspapers typically list money market fund yields weekly,  separately from
listings  for  other  mutual   funds.   Different   newspapers   use   different
abbreviations  for the Funds,  but the most  common  are  VANGPR,  VANGFDL,  and
VANGTRSY.

<PAGE>

15

FINANCIAL HIGHLIGHTS

The following  financial  highlights  tables are intended to help you understand
each  Fund's  financial  performance  for  the  past  five  years,  and  certain
information reflects financial results for a single Fund share in each case. The
total  returns  in each table  represent  the rate that an  investor  would have
earned or lost each year on an investment in the Fund (assuming  reinvestment of
all  dividend  distributions).  This  information  has  been  derived  from  the
financial   statements  audited  by   PricewaterhouseCoopers   LLP,  independent
accountants,  whose  report--along  with each  Fund's  financial  statements--is
included in the Funds' most recent annual report to  shareholders.  You may have
the annual report sent to you without charge by contacting Vanguard.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                   HOW TO READ THE FINANCIAL HIGHLIGHTS TABLES

This explanation uses the Prime Money Market Fund Investor Shares as an example.
The Fund began  fiscal 1999 with a net asset  value  (price) of $1.00 per share.
During  the year,  the Fund  earned  $0.049  per share  from  investment  income
(interest and dividends).

Shareholders  received  $0.049 per share in the form of dividend  distributions.
The  earnings  ($0.049  per share)  minus the  distributions  ($0.049 per share)
resulted in a share price of $1.00 at the end of the year. For a shareholder who
reinvested the  distributions  in the purchase of more shares,  the total return
from the Fund was 4.97% for the year.

As of November 30, 1999, the Fund had $39.4 billion in net assets. For the year,
its  expense  ratio was 0.33%  ($3.30  per  $1,000 of net  assets),  and its net
investment income amounted to 4.85% of its average net assets.

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                                        VANGUARD PRIME MONEY MARKET FUND
                                                INVESTOR SHARES
                                            YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                           1999        1998        1997        1996        1995
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF YEAR        $1.00       $1.00       $1.00       $1.00       $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income     .049        .053        .053        .052        .057
 Net Realized and
  Unrealized Gain (Loss)
  on Investments             --          --          --          --          --
                        --------------------------------------------------------
   Total from Investment
    Operations             .049        .053        .053        .052        .057
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income       (.049)      (.053)      (.053)      (.052)      (.057)
 Distributions from
  Realized Capital
  Gains                      --          --          --          --          --
                        --------------------------------------------------------
   Total Distributions    (.049)      (.053)      (.053)      (.052)      (.057)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF YEAR                  $1.00       $1.00       $1.00       $1.00       $1.00
================================================================================

TOTAL RETURN              4.97%       5.42%       5.41%       5.31%       5.82%
================================================================================
RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)       $39,430     $33,732     $26,480     $22,218     $18,764
 Ratio of Total
  Expenses to Average
  Net Assets              0.33%       0.33%       0.32%       0.32%       0.32%
 Ratio of Net
  Investment Income to
  Average Net Assets      4.85%       5.28%       5.28%       5.18%       5.64%
================================================================================


<PAGE>

16


- --------------------------------------------------------------------------------
                                    VANGUARD FEDERAL MONEY MARKET FUND
                                         YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                           1999        1998        1997        1996        1995
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF YEAR        $1.00       $1.00       $1.00       $1.00       $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income     .048        .052        .052        .051        .056
 Net Realized and
  Unrealized Gain (Loss)
  on Investments             --          --          --          --          --
                        --------------------------------------------------------
   Total from Investment
    Operations             .048        .052        .052        .051        .056
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income       (.048)      (.052)      (.052)      (.051)      (.056)
 Distributions from
  Realized Capital Gains     --          --          --          --          --
                        --------------------------------------------------------
   Total Distributions    (.048)      (.052)      (.052)      (.051)      (.056)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF YEAR                  $1.00       $1.00       $1.00       $1.00       $1.00
================================================================================

TOTAL RETURN              4.89%       5.35%       5.35%       5.26%       5.77%
================================================================================

RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)        $5,243      $4,263      $3,495      $3,100      $2,637
 Ratio of Total
  Expenses to Average
  Net Assets              0.33%       0.33%       0.32%       0.32%       0.32%
 Ratio of Net
  Investment Income to
  Average Net Assets      4.79%       5.21%       5.22%       5.13%       5.61%
================================================================================

- --------------------------------------------------------------------------------
                                   VANGUARD TREASURY MONEY MARKET FUND
                                         YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                           1999        1998        1997        1996        1995
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF YEAR        $1.00       $1.00       $1.00       $1.00       $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income     .044        .050        .050        .050        .053
 Net Realized and
  Unrealized Gain (Loss)
  on Investments             --          --          --          --          --
                        --------------------------------------------------------
   Total from Investment
    Operations             .044        .050        .050        .050        .053
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income       (.044)      (.050)      (.050)      (.050)      (.053)
 Distributions from
  Realized Capital Gains     --          --          --          --          --
                        --------------------------------------------------------
   Total Distributions    (.044)      (.050)      (.050)      (.050)      (.053)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF YEAR                  $1.00       $1.00       $1.00       $1.00       $1.00
================================================================================

TOTAL RETURN              4.51%       5.06%       5.10%       5.11%       5.47%
================================================================================

RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)        $4,593      $3,942      $3,237      $2,917      $2,527
 Ratio of Total
  Expenses to Average
  Net Assets              0.33%       0.33%       0.32%       0.32%       0.32%
 Ratio of Net
  Investment Income to
  Average Net Assets      4.41%       4.94%       4.98%       4.99%       5.33%
================================================================================


"Standard & Poor's(R),"  "S&P(R),"  "S&P  500(R),"  "Standard & Poor's 500," and
"500" are trademarks of The McGraw-Hill Companies, Inc.

<PAGE>

17

INVESTING WITH VANGUARD

One or more of the Funds is an investment  option in your  retirement or savings
plan. Your plan  administrator or your employee  benefits office can provide you
with detailed  information on how to participate in your plan and how to elect a
Fund as an  investment  option.

- -    If you have any questions  about a Fund or Vanguard,  including those about
     the Fund's investment objective,  strategies,  or risks, contact Vanguard's
     Participant Services Center, toll-free, at 1-800-523-1188.

- -    If you have questions about your account,  contact your plan  administrator
     or the organization that provides recordkeeping services for your plan.

INVESTMENT OPTIONS AND ALLOCATIONS

Your  plan's  specific  provisions  may  allow  you to  change  your  investment
selections,  the amount of your  contributions,  or how your  contributions  are
allocated  among the  investment  choices  available  to you.  Contact your plan
administrator or employee benefits office for more details.

TRANSACTIONS

Contributions,  exchanges,  or  redemptions  of a Fund's shares are processed as
soon as they have been received by Vanguard in good order. Good order means that
your request includes complete  information on your contribution,  exchange,  or
redemption, and that Vanguard has received the appropriate assets.

EXCHANGES

The exchange  privilege (your ability to redeem shares from one fund to purchase
shares of another  fund) may be available to you through your plan.  Although we
make every  effort to maintain  the exchange  privilege,  Vanguard  reserves the
right to revise or terminate this privilege,  limit the amount of an exchange or
reject any exchange, at any time, without notice.

ACCESSING FUND INFORMATION BY COMPUTER
- --------------------------------------------------------------------------------
VANGUARD ON THE WORLD WIDE WEB www.vanguard.com
Use your personal computer to visit Vanguard's education-oriented website, which
provides  timely news and  information  about  Vanguard  funds and services;  an
online  "university"  that  offers  a  variety  of  mutual  fund  classes;   and
easy-to-use,  interactive  tools to help you  create  your  own  investment  and
retirement strategies.
- --------------------------------------------------------------------------------

<PAGE>

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<PAGE>

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<PAGE>

                      (THIS PAGE INTENTIONALLY LEFT BLANK.)

<PAGE>

GLOSSARY OF INVESTMENT TERMS

DIVIDEND INCOME
Payment to  shareholders  of income from  interest or  dividends  generated by a
fund's investments.

EXPENSE RATIO
The  percentage  of a fund's  average net assets used to pay its  expenses.  The
expense ratio  includes  management  fees,  administrative  fees,  and any 12b-1
distribution fees.

INVESTMENT ADVISER
An  organization  that  makes  the  day-to-day   decisions  regarding  a  fund's
investments.

LIQUIDITY
The degree of a security's  marketability (that is, how quickly the security can
be sold at a fair price and converted to cash).

MONEY MARKET FUND
A mutual fund that seeks to provide income,  liquidity, and a stable share price
by investing in very short-term, liquid investments.

MONEY MARKET INSTRUMENTS
Short-term,  liquid  investments (usually with a maturity of 13 months or less),
which  include  U.S.   Treasury  bills,  bank  certificates  of  deposit  (CDs),
repurchase agreements, commercial paper, and banker's acceptances.

MUTUAL FUND
An  investment  company  that pools the money of many people and invests it in a
variety of securities in an effort to achieve a specific objective over time.

NET ASSET VALUE (NAV)
The market value of a mutual fund's total assets, minus liabilities,  divided by
the  number of shares  outstanding.  The value of a single  share is called  its
share value or share price.

PRINCIPAL
The amount of money you put into an investment.

SECURITIES
Stocks,  bonds,  money market  instruments,  and  interests in other  investment
vehicles.

TOTAL RETURN
A percentage change,  over a specified time period, in a mutual fund's net asset
value,  with the ending net asset value adjusted to account for the reinvestment
of all distributions of dividends and capital gains.

VOLATILITY
The  fluctuations  in value of a mutual  fund or other  security.  The greater a
fund's volatility, the wider the fluctuations between its high and low prices.

YIELD
Income  (interest  or  dividends)  earned  by  an  investment,  expressed  as  a
percentage of the investment's price.

<PAGE>


                                                    [SHIP(R) LOGO]
                                                    [THE VANGUARD GROUP(R) LOGO]

                                                    Institutional Division
                                                    Post Office Box 2900
                                                    Valley Forge, PA 19482-2900

FOR MORE INFORMATION
If you'd like more information about
Vanguard Money Market Funds, the
following documents are available
free upon request:

ANNUAL/SEMIANNUAL REPORT
TO SHAREHOLDERS
Additional information about the
Funds' investments is available in
the Funds' annual and semiannual
reports to shareholders.

STATEMENT OF ADDITIONAL
INFORMATION (SAI)
The SAI provides more detailed
information about the Funds.

The current annual and semiannual
reports and the SAI are
incorporated by reference into
(and are thus legally a part of)
this prospectus.

To receive a free copy of the latest
annual or semiannual report or the
SAI, or to request additional
information about the Funds or other
Vanguard funds, please contact us
as follows:

THE VANGUARD GROUP
PARTICIPANT SERVICES CENTER
P.O. BOX 2900
VALLEY FORGE, PA 19482-2900

TELEPHONE:
1-800-523-1188

TEXT TELEPHONE:
1-800-523-8004

WORLD WIDE WEB:
WWW.VANGUARD.COM

INFORMATION PROVIDED BY THE
SECURITIES AND EXCHANGE
COMMISSION (SEC)
You can review and copy
information about the Funds
(including the SAI) at the SEC's
Public Reference Room in
Washington, DC. To find out more
about this public service, call the
SEC at 1-800-SEC-0330. Reports and
other information about the Funds
are also available on the SEC's
website (www.sec.gov), or you can
receive copies of this information,
for a fee, by writing the Public
Reference Section, Securities and
Exchange Commission, Washington,
DC 20549-0102.

Vanguard Prime and Federal Money
Market Funds' Investment Company
Act file number: 811-2554

Vanguard Treasury Money Market
Fund's Investment Company Act file
number: 811-7803

(C) 2000 The Vanguard Group, Inc.
All rights reserved.
Vanguard Marketing Corporation,
Distributor.

I030N-03/24/2000



<PAGE>



                                                            VANGUARD(R) PRIME
                                                            MONEY MARKET FUND
                                                            INSTITUTIONAL SHARES

                                                            Prospectus
                                                            March 24, 2000

This prospectus contains
financial data for the
Fund through the
fiscal year ended
November 30, 1999.

                                                                    [A MEMBER OF
                                                        THE VANGUARD GROUP LOGO]

<PAGE>

VANGUARD PRIME MONEY MARKET FUND
INSTITUTIONAL SHARES

Prospectus

March 24, 2000




- --------------------------------------------------------------------------------
    CONTENTS
- --------------------------------------------------------------------------------

  1 FUND PROFILE                             11 INVESTING WITH VANGUARD

  4 ADDITIONAL INFORMATION                      11 Services and Account Features

  4 A WORD ABOUT RISK                           12 Types of Accounts

  4 WHO SHOULD INVEST                           12 Buying Shares

  5 PRIMARY INVESTMENT POLICIES                 14 Redeeming Shares

  7 THE FUND AND VANGUARD                       17 Transferring Registration

  8 INVESTMENT ADVISER                          17 Fund and Account Updates

  8 DIVIDENDS AND TAXES                         18 Mandatory Conversion to
                                                   Investor Shares
  9 SHARE PRICE
                                             GLOSSARY (inside back cover)
 10 FINANCIAL HIGHLIGHTS

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
WHY READING THIS PROSPECTUS IS IMPORTANT

This prospectus  explains the objective,  risks,  and policies of Vanguard Prime
Money  Market  Fund  Institutional  Shares.  To  highlight  terms  and  concepts
important  to  mutual  fund   investors,   we  have  provided   "Plain  Talk(R)"
explanations  along  the way.  Reading  the  prospectus  will help you to decide
whether the Fund is the right  investment  for you. We suggest  that you keep it
for future reference.
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
IMPORTANT NOTE

The Prime Money Market Fund offers two separate classes of shares:  Investor and
Institutional.  This prospectus offers the Fund's  Institutional  Shares,  which
have an  investment  minimum of $10 million and  generally  are not available to
investors  who require  special  employee  benefit  plan  services.  Please call
Vanguard  at  1-800-662-7447  to obtain a separate  prospectus  that  offers the
Fund's Investor Shares,  which have an investment  minimum of $3,000 ($1,000 for
IRA's).

     The Fund's  separate  share classes have different  expenses;  as a result,
their investment  performances will vary. UNLESS OTHERWISE NOTED, ALL REFERENCES
IN  THIS  PROSPECTUS  TO  FEES,  EXPENSES,  AND  INVESTMENT  PERFORMANCE  RELATE
SPECIFICALLY TO INSTITUTIONAL SHARES.

- --------------------------------------------------------------------------------


NEITHER  THE  SECURITIES  AND  EXCHANGE  COMMISSION  NOR  ANY  STATE  SECURITIES
COMMISSION HAS APPROVED OR  DISAPPROVED  OF THESE  SECURITIES OR PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

<PAGE>

1

FUND PROFILE

The following  profile  summarizes  key features of Vanguard  Prime Money Market
Fund Institutional Shares.

INVESTMENT OBJECTIVE

The Fund seeks to provide  current  income  while  maintaining  liquidity  and a
stable share price of $1.

INVESTMENT POLICIES

The Fund invests primarily in high-quality, short-term money market instruments,
including certificates of deposit,  banker's acceptances,  commercial paper, and
other  money  market  securities.  To be  considered  high  quality,  a security
generally must be rated in one of the two highest credit-quality  categories for
short-term  securities by at least two nationally recognized rating services (or
by one, if only one rating  service  has rated the  security).  If unrated,  the
security must be determined by the Fund's adviser to be of quality equivalent to
those in the two highest  credit-quality  categories.  The Fund will maintain an
average  maturity  of 90 days or  less.  For  more  information,  see  "Security
Selection" under PRIMARY INVESTMENT POLICIES.

PRIMARY RISKS

THE FUND IS SUBJECT TO INCOME RISK, WHICH IS THE CHANCE THAT FALLING  SHORT-TERM
INTEREST  RATES  WILL  CAUSE THE FUND'S  INCOME--AND  THUS ITS TOTAL  RETURN--TO
DECLINE.  INCOME  RISK IS  GENERALLY  HIGH FOR FUNDS THAT  INVEST IN  SHORT-TERM
SECURITIES. The Fund is also subject to:

- -    Manager risk,  which is the chance that poor security  selection will cause
     the Fund to underperform other funds with similar investment objectives.

- -    Credit risk, which is the chance that the issuer of a security will fail to
     pay interest and principal in a timely manner.  Credit risk,  which has the
     potential to hurt the Fund's performance, should be low for the Fund.

     AN  INVESTMENT  IN THE FUND IS NOT  INSURED OR  GUARANTEED  BY THE  FEDERAL
DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.  ALTHOUGH THE FUND
SEEKS TO PRESERVE THE VALUE OF YOUR  INVESTMENT AT $1 PER SHARE,  IT IS POSSIBLE
TO LOSE MONEY BY INVESTING IN THE FUND.

PERFORMANCE/RISK INFORMATION

The bar chart and table below  provide an indication of the risk of investing in
the Fund. The bar chart shows the Fund's  performance in each calendar year over
a ten-year  period.  The table shows how the Fund's average annual total returns
for one, five, and ten calendar years compare with those of a broad-based  money
market index.  Keep in mind that the Fund's past  performance  does not indicate
how it will perform in the future.


<PAGE>

2

              ----------------------------------------------------
                              ANNUAL TOTAL RETURNS
              ----------------------------------------------------

                              1990           8.43%
                              1991           6.26%
                              1992           3.88%
                              1993           3.18%
                              1994           4.27%
                              1995           6.01%
                              1996           5.46%
                              1997           5.61%
                              1998           5.57%
                              1999           5.20%

              ----------------------------------------------------
              NOTE: Prior to October 28, 1995, total returns are
               for Vanguard Institutional Money Market Portfolio.
              ----------------------------------------------------

     During the period shown in the bar chart, the highest return for a calendar
quarter  was 2.08%  (quarter  ended June 30,  1990) and the lowest  return for a
quarter was 0.77% (quarter ended June 30, 1993).

        -----------------------------------------------------------------
         AVERAGE ANNUAL TOTAL RETURNS FOR YEARS ENDED DECEMBER 31, 1999
        -----------------------------------------------------------------
                                           1 YEAR    5 YEARS    10 YEARS
        -----------------------------------------------------------------
        Vanguard Prime Money Market Fund
         Institutional Shares               5.20%     5.57%       5.38%
        Salomon Smith Barney 3-Month
         Treasury Index                     4.74      5.20        5.05
        Average Institutional Money
         Market Fund*                       4.92      5.29        5.11
        -----------------------------------------------------------------
        *Derived from data provided by Lipper Inc.
        -----------------------------------------------------------------


     If you would like to know the current  seven-day  yield for the Fund,  call
Vanguard's Investor Information Department at 1-800-662-7447 (SHIP).

FEES AND EXPENSES

The following  table  describes the fees and expenses you may pay if you buy and
hold shares of the Fund. The expenses shown under Annual Fund Operating Expenses
are based upon those incurred in the fiscal year ended November 30, 1999.

      SHAREHOLDER FEES (fees paid directly from your investment)
      Sales Charge (Load) Imposed on Purchases:                          None
      Sales Charge (Load) Imposed on Reinvested Dividends:               None
      Redemption Fee:                                                    None
      Exchange Fee:                                                      None

      ANNUAL FUND OPERATING EXPENSES (expenses deducted from the Fund's assets)
      Management Expenses:                                              0.11%
      12b-1 Distribution Fee:                                            None
      Other Expenses:                                                   0.04%
       TOTAL ANNUAL FUND OPERATING EXPENSES:                            0.15%


<PAGE>

3

     The following example is intended to help you compare the cost of investing
in the Fund with the cost of investing in other mutual funds. It illustrates the
hypothetical  expenses  that you would incur over various  periods if you invest
$10,000 in the Fund.  This example assumes that the Fund provides a return of 5%
a year, and that operating  expenses  remain the same. The results apply whether
or not you redeem your investment at the end of each period.

- -------------------------------------------------
  1 YEAR      3 YEARS     5 YEARS      10 YEARS
- -------------------------------------------------
    $15         $48         $85          $192
- -------------------------------------------------

     THIS  EXAMPLE  SHOULD NOT BE  CONSIDERED  TO REPRESENT  ACTUAL  EXPENSES OR
PERFORMANCE  FROM THE PAST OR FOR THE  FUTURE.  ACTUAL  FUTURE  EXPENSES  MAY BE
HIGHER OR LOWER THAN THOSE SHOWN.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                  FUND EXPENSES

All mutual funds have operating  expenses.  These  expenses,  which are deducted
from a fund's gross  income,  are expressed as a percentage of the net assets of
the fund.  Vanguard Prime Money Market Fund Institutional  Shares' expense ratio
in fiscal year 1999 was 0.15%,  or $1.50 per $1,000 of average  net assets.  The
average  institutional  taxable money market mutual fund had expenses in 1999 of
0.41%,  or $4.10 per $1,000 of average net assets (derived from data provided by
Lipper Inc.,  which reports on the mutual fund industry).  Management  expenses,
which comprise one part of operating expenses,  include investment advisory fees
as well as  other  costs  of  managing  a  fund--such  as  account  maintenance,
reporting, accounting, legal, and other administrative expenses.

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                               PLAIN TALK ABOUT
                            THE COSTS OF INVESTING

Costs are an important  consideration in choosing a mutual fund.  That's because
you, as a shareholder,  pay the costs of operating a fund,  plus any transaction
costs  associated with the fund's buying and selling of securities.  These costs
can erode a substantial  portion of the gross income or capital  appreciation  a
fund achieves. Even seemingly small differences in expenses can, over time, have
a dramatic effect on a fund's performance.
- --------------------------------------------------------------------------------

<PAGE>

4

- --------------------------------------------------------------------------------
ADDITIONAL INFORMATION

DIVIDENDS                             MINIMUM INITIAL INVESTMENT
Declared daily and distributed on     $10 million
the first business day of each month
                                      NEWSPAPER ABBREVIATION
INVESTMENT ADVISER                    VangPrInst
The Vanguard Group, Valley Forge,
Pa., since inception                  VANGUARD FUND NUMBER
                                      066
INCEPTION DATE*
October 3, 1989                       CUSIP NUMBER
                                      922906508
NET ASSETS AS OF NOVEMBER 30, 1999
$41.2 billion                         TICKER SYMBOL
                                      VMRXX
SUITABLE FOR IRAS
Yes                                   *The Institutional Shares were originally
                                       created as a separate fund. On October
                                       28, 1995,  they became a separate share
                                       class of the Prime Money Market Fund.

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
A WORD ABOUT RISK

This prospectus  describes risks you would face as an investor in Vanguard Prime
Money Market Fund  Institutional  Shares. It is important to keep in mind one of
the main axioms of investing:  The higher the risk of losing  money,  the higher
the potential reward. The reverse,  also, is generally true: The lower the risk,
the lower the potential reward.

     Look for this [FLAG] symbol  throughout the prospectus.  It is used to mark
detailed  information  about  each  type of risk that you  would  confront  as a
shareholder of the Fund.
- --------------------------------------------------------------------------------

WHO SHOULD INVEST

The Fund may be a suitable investment for you if:

- -    You wish to add a money market fund to your existing holdings,  which could
     include other cash--as well as stock, bond, and tax-exempt--investments.

- -    You want an investment that does not fluctuate in value.

- -    You want current income.

COSTS AND MARKET-TIMING

The Vanguard  Prime Money Market Fund serves both short- and long-term  investor
needs; however,  other Vanguard funds are intended for long-term investors only.
Investors  who  engage  in  excessive   in-and-out   trading  activity  generate
additional  costs that are borne by all of a fund's  shareholders.  To  minimize
these costs, Vanguard's stock, bond, and balanced funds have adopted policies to
discourage short-term  trading--which includes switching back and forth from the
Prime Money Market Fund.  Please check other Vanguard  funds'  prospectuses  for
specifics on the trading  limitations of those funds.  Also, all Vanguard funds,
including this Fund, reserve the right to stop offering shares at any time or to
reject specific purchase requests.

     THE VANGUARD FUNDS DO NOT PERMIT MARKET-TIMING.  DO NOT INVEST IN THIS FUND
IF YOU ARE A MARKET-TIMER.

<PAGE>

5

PRIMARY INVESTMENT POLICIES

This section  explains the policies that the investment  adviser uses in pursuit
of the Fund's objectives--income, liquidity, and stability of principal. It also
explains how the adviser  implements these policies.  In addition,  this section
discusses  several  important  risks--income  risk,  manager  risk,  and  credit
risk--faced by investors in the Fund. The Fund's Board of Trustees  oversees the
management of the Fund, and may change the investment strategies in the interest
of shareholders.

MARKET EXPOSURE

The  Fund's  primary  policy  is to  invest in very  high-quality  money  market
instruments--also  known as cash reserves--that are considered  short-term (that
is,  they  mature  in 13 months or less).  The Fund  will  maintain  an  average
maturity of 90 days or less.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                            MONEY MARKET INSTRUMENTS

The term "money market  instruments"  refers to a variety of  short-term  liquid
investments,  usually  with a maturity of 13 months or less.  Some common  types
are:  Treasury  bills  and  notes,  which  are  securities  issued  by the  U.S.
government;  commercial  paper,  which  are  promissory  notes  issued  by large
companies or financial firms; banker's acceptances, which are credit instruments
guaranteed by a bank; and negotiable  certificates of deposit,  which are issued
by  banks in  large  denominations.  Money  market  securities  can pay a fixed,
variable, or floating rate of interest.

- --------------------------------------------------------------------------------

[FLAG] THE FUND IS SUBJECT TO INCOME  RISK,  WHICH IS THE CHANCE THAT THE FUND'S
     DIVIDENDS (THAT IS, INCOME) WILL DECLINE BECAUSE OF FALLING INTEREST RATES.
     BECAUSE THE FUND'S INCOME IS BASED ON SHORT-TERM INTEREST  RATES--WHICH CAN
     FLUCTUATE  SIGNIFICANTLY OVER SHORT  PERIODS--INCOME RISK IS EXPECTED TO BE
     HIGH.



SECURITY SELECTION

The  Vanguard  Group,  adviser to the Fund,  selects  high-quality  money market
instruments. The Fund focuses on securities of a particular class of issuer (the
U.S. government,  U.S. government agencies, or non government issuers). The Fund
is managed without regard to tax ramifications.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                 CREDIT QUALITY

A money market  instrument's credit quality depends upon the issuer's ability to
pay interest on the security and,  ultimately,  to repay the debt. The lower the
rating by one of the independent  bond-rating agencies (for example,  Moody's or
Standard & Poor's),  the greater the chance (in the rating agency's opinion) the
security's issuer will default, or fail to meet its payment obligations.  Direct
U.S. Treasury  obligations  (that is, securities issued by the U.S.  government)
carry  the  highest  credit  ratings.  All  things  being  equal,  money  market
instruments with greater credit risk offer higher yields.

- --------------------------------------------------------------------------------

<PAGE>

6


[FLAG] THE FUND IS SUBJECT TO MANAGER RISK, WHICH IS THE CHANCE THAT THE ADVISER
     MAY DO A POOR JOB OF SELECTING SECURITIES.

     The Prime Money Market Fund invests  primarily in  certificates of deposit,
banker's  acceptances,  commercial  paper,  and other money  market  securities.
Commercial  paper must be rated Prime-1 by Moody's  Investors  Service or A-1 by
Standard & Poor's  Corporation.  Securities that are unrated must be issued by a
company  with a debt  rating  of A3 or  better  by  Moody's  or A- or  better by
Standard & Poor's.  The Fund also invests in short-term  corporate,  state,  and
municipal  obligations rated A3 or better by Moody's or A- or better by Standard
& Poor's.

     Among the certificates of deposit typically held by the Fund are Eurodollar
and Yankee  obligations,  which are primarily  certificates of deposit issued in
U.S. dollars by foreign banks and foreign branches of U.S. banks. Eurodollar and
Yankee obligations have risks similar to U.S. money market instruments,  such as
income risk and credit risk.  Other risks of Eurodollar  and Yankee  obligations
include  the  possibilities  that:  a  foreign  government  will  not  let  U.S.
dollar-denominated  assets  leave the country;  the banks that issue  Eurodollar
obligations  may not be  subject  to the same  regulations  as U.S.  banks;  and
adverse political or economic  developments will affect investments in a foreign
country.  Before the Fund's adviser  selects a Eurodollar or Yankee  obligation,
however, the foreign issuer undergoes the same credit-quality analysis and tests
of financial strength as an issuer of domestic securities.

     The Fund also  invests in  securities  issued by U.S.  government  agencies
whose interest and principal payments typically are not backed by the full faith
and credit of the U.S.  government.  These agencies include,  among others,  the
Federal  Home Loan Bank,  the Federal  National  Mortgage  Association,  and the
Federal Home Loan Mortgage Corporation.

[FLAG] THE FUND IS SUBJECT,  TO A LIMITED EXTENT,  TO CREDIT RISK,  WHICH IS THE
     CHANCE  THAT  THE  ISSUER  OF A  SECURITY  WILL  FAIL TO PAY  INTEREST  AND
     PRINCIPAL IN A TIMELY MANNER.

     While the credit quality of the Fund's  portfolio  securities is very high,
the Fund faces credit risk because it invests in money market  securities issued
by private  companies.  It is possible  that one or more of these  companies may
experience financial  difficulties and, as a result, may fail to pay interest to
the Fund or return the Fund's principal when repayment is due.

     Also,  bear in mind  that,  while the Fund  invests in  high-quality  money
market  instruments,  the Fund is not insured or  guaranteed  by the FDIC or any
other agency of the U.S. government.

[FLAG] THE FUND RESERVES THE RIGHT TO INVEST IN REPURCHASE AGREEMENTS, WHICH ARE
     SUBJECT TO SPECIFIC RISKS.

- --------------------------------------------------------------------------------
                               PLAIN TALK ABOUT
                             REPURCHASE AGREEMENTS

A means  of  investing  money  for a short  period,  repurchase  agreements  are
contracts  in which a  financial  institution  sells  securities  and  agrees to
repurchase  the  securities on a specific date  (normally the next business day)
and at a specific price.

- --------------------------------------------------------------------------------

<PAGE>

7

     Repurchase  agreements carry several risks. For instance,  if the seller is
unable to repurchase the securities as promised,  the Fund may experience a loss
when trying to sell the securities to another person.  Or, if the seller becomes
insolvent, a bankruptcy court may determine that the securities do not belong to
the Fund and order that the  securities  be sold to pay off the seller's  debts.
The Fund's adviser  believes that these risks can be controlled  through careful
security selection and monitoring.

[FLAG]  THE  FUND  RESERVES  THE  RIGHT  TO  INVEST,  TO A  LIMITED  EXTENT,  IN
     FLOATING-RATE SECURITIES, WHICH ARE TRADITIONAL TYPES OF DERIVATIVES.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                                   DERIVATIVES

A derivative is a financial  contract whose value, or interest rate, is based on
(or "derived"  from) a traditional  security  (such as a stock or bond), a money
market  benchmark  (such  as U.S.  Treasury  bill  rates  or the  Federal  Funds
Effective  Rate),  an asset (such as a commodity  like gold),  or a market index
(such as the S&P 500 Index).
- --------------------------------------------------------------------------------

     A floating-rate  security's interest rate, as the name implies, is not set;
instead, it fluctuates periodically. Generally, the security's yield is based on
a U.S. dollar-based  interest-rate benchmark such as the Federal Funds Rate, the
90-day Treasury bill rate, or the London Interbank  Offered Rate (LIBOR).  These
securities reset their yields on a periodic basis (for example,  daily,  weekly,
or quarterly)  and are closely  correlated  to changes in money market  interest
rates.

     The Fund will not use derivatives for speculative  purposes or as leveraged
investments that magnify the risks of an investment.

     In  addition,  the Fund may invest up to 10% of its net assets in  illiquid
securities. These are securities that cannot be readily resold or converted into
cash.

- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                      VANGUARD'S UNIQUE CORPORATE STRUCTURE

The Vanguard Group is truly a MUTUAL mutual fund company. It is owned jointly by
the funds it oversees and thus  indirectly by the  shareholders  in those funds.
Most other mutual funds are operated by for-profit management companies that may
be owned by one person,  by a group of individuals,  or by investors who own the
management  company's stock. By contrast,  Vanguard  provides its services on an
"at-cost"  basis,  and the funds' expense  ratios  reflect only these costs.  No
separate  management  company reaps profits or absorbs losses from operating the
funds.
- --------------------------------------------------------------------------------

THE FUND AND VANGUARD

The Fund is a member of The Vanguard  Group, a family of more than 35 investment
companies  with more than 100 funds holding assets worth more than $520 billion.
All of the  Vanguard  funds  share  in the  expenses  associated  with  business
operations, such as personnel, office space, equipment, and advertising.

     Vanguard  also  provides   marketing   services  to  the  funds.   Although
shareholders do not pay sales commissions or 12b-1  distribution fees, each fund
pays its allocated share of The Vanguard Group's marketing costs.

<PAGE>

8

INVESTMENT ADVISER

The Vanguard Group (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, founded in
1974,  serves as the  Funds'  adviser  through  its Fixed  Income  Group.  As of
November 30, 1999,  Vanguard served as adviser for about $354 billion in assets.
Vanguard  manages  the Fund on an at-cost  basis,  subject to the control of the
Trustees and officers of the Fund.  For the fiscal year ended November 30, 1999,
the investment  advisory  expenses for the Fund  represented an effective annual
rate of 0.01% of its average net assets.

     The  adviser  places  all orders  for the  purchase  and sale of the Fund's
securities,  and seeks out the best available price and most favorable execution
for all transactions.


- --------------------------------------------------------------------------------
                                PLAIN TALK ABOUT
                               THE FUND'S ADVISER

The individuals responsible for overseeing the Fund's investments are:

IAN A. MACKINNON,  Managing  Director of Vanguard  and  head of Vanguard's Fixed
Income  Group;  has  worked  in  investment   management  since  1974;   primary
responsibility for Vanguard's  internal  fixed-income  policy and strategy since
1981; B.A., Lafayette College; M.B.A., Pennsylvania State University.

ROBERT F.  AUWAERTER,  Principal  of Vanguard  and Fund  Manager;  has worked in
investment  management since 1978; has managed portfolio investments since 1979;
B.S., University of Pennsylvania; M.B.A., Northwestern University.

JOHN HOLLYER,  Principal of Vanguard and Fund Manager;  has worked in investment
management  since 1987;  has managed  portfolio  investments  since 1989;  B.S.,
University of Pennsylvania.

DAVID  R.  GLOCKE,  Principal  of  Vanguard  and Fund  Manager;  has  worked  in
investment  management since 1991; has managed portfolio investments since 1997;
B.S., University of Wisconsin.

Mr.  Auwaerter,  Mr.  Hollyer,  and Mr.  Glocke  manage the Fund on a day-to-day
basis.  Mr.  MacKinnon is  responsible  for setting the Fund's broad  investment
policies and for overseeing the Fund Managers.
- --------------------------------------------------------------------------------



DIVIDENDS AND TAXES

FUND DISTRIBUTIONS

The Fund  distributes to shareholders  virtually all of its net income (interest
less expenses).  The Fund's income dividends accrue daily and are distributed on
the first business day of every month.  You can receive your income dividends in
cash, or you can have them automatically reinvested in more shares of the Fund.

BASIC TAX POINTS

Vanguard will send you a statement  each year showing the tax status of all your
distributions.  In addition,  taxable investors should be aware of the following
basic tax points:

- -    Distributions are taxable to you for federal income tax purposes whether or
     not you reinvest these amounts in additional Fund shares.

- -    Distributions   declared  in  December--if  paid  to  you  by  the  end  of
     January--are  taxable  for  federal  income tax  purposes as if received in
     December.


<PAGE>

9


- -    Any  dividends  that you receive are taxable to you as ordinary  income for
     federal income tax purposes.

- -    Dividend  distributions  that you receive may be subject to state and local
     income  taxes.  Depending on your state's  rules,  however,  any  dividends
     attributable to interest earned on direct  obligations of the U.S. Treasury
     may be exempt  from state and local  taxes.  Vanguard  will notify you each
     year how much, if any, of your dividends may qualify for this exemption.

GENERAL INFORMATION

BACKUP  WITHHOLDING.   By  law,  Vanguard  must  withhold  31%  of  any  taxable
distributions  or redemptions from your account if you do not:

- -    provide us with your correct taxpayer identification number;

- -    certify that the taxpayer identification number is correct; and

- -    confirm that you are not subject to backup withholding.

Similarly,  Vanguard  must withhold from your account if the IRS instructs us to
do so.

FOREIGN  INVESTORS.  The Vanguard funds  generally do not offer their shares for
sale outside of the United States.  Foreign  investors should be aware that U.S.
withholding and estate taxes may apply to any investments in Vanguard funds.

INVALID  ADDRESSES.  If a dividend or capital gains distribution check mailed to
your address of record is returned as undeliverable, Vanguard will automatically
reinvest  all future  distributions  until you  provide us with a valid  mailing
address.

TAX CONSEQUENCES.  This prospectus provides general tax information only. If you
are investing through a tax-deferred retirement account, such as an IRA, special
tax rules apply. Please consult your tax adviser for detailed  information about
a fund's tax consequences for you.




SHARE PRICE

The Fund's share price,  called its net asset value,  or NAV, is calculated each
business day after the close of regular  trading on the New York Stock  Exchange
(the NAV is not  calculated  on  holidays  or other  days when the  Exchange  is
closed).  The Fund's NAV is expected to remain at a constant  $1.  Although  the
stable share price is not  guaranteed,  the Fund is managed and  securities  are
purchased to maintain that price.

     The instruments held by the Fund are valued on the basis of amortized cost,
which does not take into account unrealized capital gains or losses.

     Newspapers typically list money market fund yields weekly,  separately from
listings  for  other  mutual   funds.   Different   newspapers   use   different
abbreviations for the Fund, but the most common is VANGPRINST.


<PAGE>

10

FINANCIAL HIGHLIGHTS

The following financial  highlights table is intended to help you understand the
Fund's financial  performance since inception,  and certain information reflects
financial  results  for a single  Fund  share.  The total  returns  in the table
represent  the rate that an  investor  would have earned or lost each year on an
investment in the Fund (assuming  reinvestment  of all dividend  distributions).
This  information  has been derived  from the  financial  statements  audited by
PricewaterhouseCoopers  LLP, independent  accountants,  whose report--along with
the Fund's  financial  statements--is  included in the Fund's most recent annual
report to  shareholders.  You may have the  annual  report  sent to you  without
charge by contacting Vanguard.


- --------------------------------------------------------------------------------
                               PLAIN TALK ABOUT
                  HOW TO READ THE FINANCIAL HIGHLIGHTS TABLE

The Fund began  fiscal 1999 with a net asset  value  (price) of $1.00 per share.
During  the year,  the Fund  earned  $0.050  per share  from  investment  income
(interest and dividends).

Shareholders  received  $0.050 per share in the form of dividend  distributions.
The  earnings  ($0.050  per share)  minus the  distributions  ($0.050 per share)
resulted in a share price of $1.00 at the end of the year. For a shareholder who
reinvested the  distributions  in the purchase of more shares,  the total return
from the Fund's Institutional Shares was 5.15% for the year.

As of November 30, 1999, the Fund's Institutional Shares had $1.8 billion in net
assets.  For the year,  its  expense  ratio was 0.15%  ($1.50  per $1,000 of net
assets);  and its net  investment  income  amounted  to 5.04% of its average net
assets.

- --------------------------------------------------------------------------------
                                    VANGUARD PRIME MONEY MARKET FUND
                                          INSTITUTIONAL SHARES
                                         YEAR ENDED NOVEMBER 30,
                        --------------------------------------------------------
                         1999         1998        1997        1996         1995*
- --------------------------------------------------------------------------------
NET ASSET VALUE,
 BEGINNING OF PERIOD    $1.00        $1.00       $1.00       $1.00        $1.00
- --------------------------------------------------------------------------------
INVESTMENT OPERATIONS
 Net Investment Income   .050         .055        .054        .054         .005
 Net Realized and
  Unrealized Gain (Loss)
  on Investments           --           --          --          --           --
                        --------------------------------------------------------
   Total from Investment
    Operations           .050         .055        .054        .054         .005
                        --------------------------------------------------------
DISTRIBUTIONS
 Dividends from Net
  Investment Income     (.050)       (.055)      (.054)      (.054)       (.005)
 Distributions from
  Realized Capital Gains   --           --          --          --           --
                        --------------------------------------------------------
   Total Distributions  (.050)       (.055)      (.054)      (.054)       (.005)
- --------------------------------------------------------------------------------
NET ASSET VALUE, END
 OF PERIOD              $1.00        $1.00       $1.00       $1.00        $1.00
================================================================================

TOTAL RETURN            5.15%        5.61%       5.59%       5.49%        0.53%
================================================================================

RATIOS/SUPPLEMENTAL DATA
 Net Assets, End of
  Year (Millions)      $1,776       $1,143        $951        $910         $793
 Ratio of Total
  Expenses to Average
  Net Assets            0.15%        0.15%       0.15%       0.15%      0.15%**
 Ratio of Net Investment
  Income to Average
  Net Assets            5.04%        5.46%       5.44%       5.35%      5.65%**
================================================================================

 *Period began on the Fund's inception date, October 28, 1995.
**Annualized.

"Standard & Poor's(R),"  "S&P(R),"  "S&P  500(R),"  "Standard & Poor's 500," and
"500" are trademarks of The McGraw-Hill Companies, Inc.

<PAGE>

11

- --------------------------------------------------------------------------------
INVESTING WITH VANGUARD

Are you looking for the most  convenient  way to open or add money to a Vanguard
account? Obtain instant access to fund information?

     Vanguard  can help.  Our goal is to make it easy and pleasant for you to do
business with us.

     The following  sections of the prospectus briefly explain the many services
we offer.  Booklets providing detailed information are available on the services
marked with a [BOOK]. Please call us to request copies.
- --------------------------------------------------------------------------------

SERVICES AND ACCOUNT FEATURES
Vanguard  offers many services that make it convenient to buy, sell, or exchange
shares, or to obtain fund or account information.
- --------------------------------------------------------------------------------
TELEPHONE REDEMPTIONS (SALES AND EXCHANGES)
Automatically set up for this Fund unless you notify us otherwise.
- --------------------------------------------------------------------------------
VANGUARD(R) AUTOMATIC EXCHANGE SERVICE [BOOK]
Automatic  method for  moving a fixed  amount of money  from one  Vanguard  fund
account to another.
- --------------------------------------------------------------------------------
VANGUARD TELE-ACCOUNT(R) 1-800-662-6273 (ON-BOARD) [BOOK]

Toll-free  24-hour access to Vanguard fund and account  information--as  well as
some  transactions--by  using any touch-tone phone.  Tele-Account provides total
return,  share price, price change, and yield quotations for all Vanguard funds;
gives your account balances and history (e.g., last transaction, latest dividend
distribution);  and  allows  you to sell or  exchange  shares  to and from  most
Vanguard funds.

- --------------------------------------------------------------------------------
ACCESS VANGUARD(TM) www.vanguard.com [COMPUTER]

You can use your  personal  computer to perform  certain  transactions  for most
Vanguard  funds by accessing our website.  To establish  this service,  you must
register  through our website.  We will then mail you an account access password
that  allows  you  to  process  the  following   financial  and   administrative
transactions  online:
- -    Open a new account.*
- -    Buy, sell, or exchange shares of most funds.
- -    Change your name/address.
- -    Add/change fund options (including dividend options, Vanguard Fund Express,
     bank instructions,  checkwriting, and Vanguard Automatic Exchange Service).
     (Some  restrictions may apply.) Please call our Client Services  Department
     for assistance.

*Only current Vanguard shareholders can open a new account online, by exchanging
 shares from other existing Vanguard accounts.
- --------------------------------------------------------------------------------
SERVICES FOR CLIENTS OF VANGUARD'S INSTITUTIONAL DIVISION 1-888-809-8102
Vanguard's  Institutional  Division offers a variety of specialized services for
large  institutional   investors,   including  the  ability  to  effect  account
transactions through private electronic networks.
- --------------------------------------------------------------------------------

<PAGE>

12

TYPES OF ACCOUNTS

Individuals and institutions can establish a variety of accounts with Vanguard.
- --------------------------------------------------------------------------------
FOR ONE OR MORE PEOPLE
Open an account in the name of one (individual) or more (joint tenants) people.
- --------------------------------------------------------------------------------
FOR HOLDING PERSONAL TRUST ASSETS [BOOK]
Invest assets held in an existing personal trust.
- --------------------------------------------------------------------------------
FOR AN ORGANIZATION [BOOK]
Open an account as a corporation,  partnership,  endowment, foundation, or other
entity.
- --------------------------------------------------------------------------------
A NOTE ON INVESTING WITH VANGUARD THROUGH OTHER FIRMS
You may purchase or sell Fund shares through a financial  intermediary such as a
bank,  broker,  or investment  adviser.  If you invest with Vanguard  through an
intermediary,  please read that firm's program  materials  carefully to learn of
any  special  rules  that may apply.  For  example,  special  terms may apply to
additional service features, fees, or other policies.  Consult your intermediary
to determine when your order will be priced.
- --------------------------------------------------------------------------------


BUYING SHARES

You buy your shares at the Fund's  next-determined share price (net asset value)
after Vanguard receives your request,  which should be $1 per share. Before your
contribution  to a money  market fund can be  invested,  it must be converted to
"federal  funds,"  which  are  Federal  Reserve  deposits  that  banks and other
financial  institutions  draw upon to meet short-term cash needs--and which fund
advisers must use to pay for the  securities  they buy.  Vanguard  converts your
money market investment to federal funds,  which usually takes one business day.
Because of this conversion period, your money market account will be credited on
the business day following the day your  investment is received.  You will begin
earning  dividends on your investment on the next calendar day. For example,  if
your check is received on a Thursday before the close of trading on the New York
Stock exchange, your account will be credited the next business day (Friday) and
you will begin earning dividends on Saturday.

     You may  convert  Investor  Shares  of the Fund into  Institutional  Shares
provided  that  you  meet  the  minimum  initial  investment   requirements  for
Institutional Shares.
- --------------------------------------------------------------------------------
MINIMUM INVESTMENT TO . . .
open a new account
$10 million

add to an existing account
$100 by mail or exchange; $1,000 by wire.
- --------------------------------------------------------------------------------
BY WIRE TO OPEN A NEW ACCOUNT OR ADD TO AN EXISTING ACCOUNT [WIRE]
Call your assigned Service Associate to arrange your wire transaction.

Wire to:
FRB ABA 021001088

HSBC Bank USA


<PAGE>

13

For credit to:
Account: 000112046
Vanguard Incoming Wire Account

In favor of:
Vanguard Prime Money Market Fund Institutional Shares-66
[Account number, or temporary number for a new account]
[Registered account owner(s)]
[Registered address]

If you buy fund shares  through a federal  funds wire,  your  investment  begins
earning  dividends  the next  calendar  day.  You can  begin  earning  dividends
immediately if you notify Vanguard by 10:45 a.m. Eastern time that you intend to
make a wire purchase that day.
- --------------------------------------------------------------------------------
BY MAIL TO . . . [ENVELOPE]
open a new account

Complete and sign the account registration form and enclose your check.

add to an existing account
Mail your check with an  Invest-By-Mail  form  detached  from your  confirmation
statement to the address listed on the form. Please do not alter  Invest-By-Mail
forms, since they are fund- and account-specific.

Make your check payable to: The Vanguard Group-66
All purchases must be made in U.S. dollars, and checks must be drawn on U.S.
banks.

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 2900                100 Vanguard Boulevard
Valley Forge, PA 19482-2900  Malvern, PA 19355-2331
- --------------------------------------------------------------------------------
IMPORTANT  NOTE:  To prevent  check fraud,  Vanguard will not accept checks made
payable to third parties.
- --------------------------------------------------------------------------------
BY TELEPHONE TO . . . [TELEPHONE]
open a new account

Call Vanguard  Tele-Account* 24 hours a day--or your assigned Service  Associate
during business  hours--to  exchange from another Vanguard fund account with the
same registration (name, address,  taxpayer  identification  number, and account
type). (Note that some restrictions apply to index fund accounts.)

add to an existing account

Call Vanguard  Tele-Account* 24 hours a day--or your assigned Service  Associate
during business  hours--to  exchange from another Vanguard fund account with the
same registration (name, address,  taxpayer  identification  number, and account
type). (Note that some restrictions apply to index fund accounts.)

Vanguard Tele-Account
1-800-662-6273

*You must obtain a Personal  Identification Number (PIN) through Tele-Account at
 least seven days before you request your first exchange.

- --------------------------------------------------------------------------------

<PAGE>

14

- --------------------------------------------------------------------------------

IMPORTANT NOTE: Once you have initiated a telephone transaction and a
confirmation number has been assigned, the transaction cannot be revoked. We
reserve the right to refuse any purchase request.

- --------------------------------------------------------------------------------
You can redeem (that is, sell or exchange) shares  purchased by check.  However,
while your redemption request will be processed at the next-determined net asset
value after it is received, your redemption proceeds will not be available until
payment for your purchase is collected, which may take up to ten calendar days.
- --------------------------------------------------------------------------------
A NOTE ON LARGE PURCHASES

It is important that you call Vanguard  before you invest a large dollar amount.
It is our responsibility to consider the interests of all Fund shareholders, and
so we  reserve  the right to refuse any  purchase  that may  disrupt  the Fund's
operation or performance.

- --------------------------------------------------------------------------------


REDEEMING SHARES

This section describes how you can redeem--that is, sell or exchange--the Fund's
shares.

When Selling Shares:
- -    Vanguard sends the redemption proceeds to you or a designated third party.*
- -    You can sell all or part of your Fund shares at any time.

*May require a signature guarantee; see footnote on page 17.

When Exchanging Shares:
- -    The redemption proceeds are used to purchase shares of a different Vanguard
     fund.
- -    You must meet the receiving fund's minimum investment requirements.
- -    Vanguard reserves the right to revise or terminate the exchange  privilege,
     limit the amount of an exchange, or reject an exchange at any time, without
     notice.

- -    In  order  to  exchange  into  an  account  with a  different  registration
     (including a different name, address, or taxpayer  identification  number),
     you must include the guaranteed signatures of all current account owners on
     your written instructions.

In both  cases,  your  transaction  will be based on the Fund's  next-determined
share price, subject to any special rules discussed in this prospectus.
- --------------------------------------------------------------------------------
NOTE: Once a redemption is initiated and a confirmation number given, the
transaction CANNOT be canceled.

- --------------------------------------------------------------------------------

HOW TO REQUEST A REDEMPTION
You can request a  redemption  from your Fund  account in any one of three ways:
online, by telephone, or by mail.

     The Vanguard funds whose shares you cannot  exchange online or by telephone
are VANGUARD U.S.  STOCK INDEX FUNDS,  VANGUARD  BALANCED  INDEX FUND,  VANGUARD
INTERNATIONAL  STOCK INDEX FUNDS,  VANGUARD REIT INDEX FUND, and VANGUARD GROWTH
AND INCOME FUND. These funds do, however,  permit online and telephone exchanges
within  IRAs and some other  retirement  accounts.  If you sell  shares of these
funds online, a redemption check will be sent to your address of record.

- --------------------------------------------------------------------------------

<PAGE>

15

- --------------------------------------------------------------------------------
ONLINE REQUESTS [COMPUTER]
ACCESS VANGUARD at www.vanguard.com

You can use your personal  computer to sell or exchange  shares of most Vanguard
funds by accessing our website.  To establish  this  service,  you must register
through our website.  We will then mail you an account access password that will
enable  you to sell  or  exchange  shares  online  (as  well  as  perform  other
transactions).

- --------------------------------------------------------------------------------
TELEPHONE REQUESTS [TELEPHONE]
Call Vanguard  Tele-Account 24 hours a day--or your assigned  Service  Associate
during business  hours--to sell or exchange shares. You can exchange shares from
this Fund to open an account in another  Vanguard  fund or to add to an existing
Vanguard fund account with an identical registration.
- --------------------------------------------------------------------------------
SPECIAL  INFORMATION:  We will automatically  establish the telephone redemption
option for your  account,  unless you instruct us  otherwise  in writing.  While
telephone  redemption is easy and convenient,  this account  feature  involves a
risk of loss from  unauthorized or fraudulent  transactions.  Vanguard will take
reasonable  precautions  to protect your  account from fraud.  You should do the
same by keeping your account information  private and immediately  reviewing any
account  statements  that  we  send  to  you.  Make  sure  to  contact  Vanguard
immediately about any transaction you believe to be unauthorized.
- --------------------------------------------------------------------------------
We reserve the right to refuse a telephone redemption if the caller is unable to
provide:
- -    The ten-digit account number.
- -    The name and address exactly as registered on the account.
- -    The primary Social Security or employer identification number as registered
     on the account.

- -    The Personal  Identification  Number (PIN),  if applicable  (for  instance,
     Tele-Account).

     Please note that Vanguard will not be  responsible  for any account  losses
due to telephone  fraud, so long as we have taken reasonable steps to verify the
caller's identity.  If you wish to remove the telephone  redemption feature from
your account, please notify us in writing.
- --------------------------------------------------------------------------------
A NOTE ON  UNUSUAL  CIRCUMSTANCES
Vanguard  reserves the right to revise or  terminate  the  telephone  redemption
privilege at any time,  without notice.  In addition,  Vanguard can stop selling
shares or postpone  payment at times when the New York Stock  Exchange is closed
or under any emergency  circumstances  as determined by the U.S.  Securities and
Exchange Commission.  If you experience difficulty making a telephone redemption
during  periods  of  drastic  economic  or market  change,  you can send us your
request  by  regular or express  mail.  Follow  the  instructions  on selling or
exchanging shares by mail in this section.
- --------------------------------------------------------------------------------
MAIL REQUESTS [ENVELOPE]
Send a letter of instruction signed by all registered  account holders.  Include
the fund name and  account  number and (if you are  selling) a dollar  amount or
number  of shares  OR (if you are  exchanging)  the name of the fund you want to
exchange  into and a dollar  amount or number of  shares.  To  exchange  into an
account  with a different  registration  (including a different  name,  address,
taxpayer identification number, or account type), you must provide Vanguard with
written  instructions  that  include the  guaranteed  signatures  of all current
owners of the fund from which you wish to redeem.

<PAGE>

16

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 2900                100 Vanguard Boulevard
Valley Forge, PA 19482-2900  Malvern, PA 19355-2331
- --------------------------------------------------------------------------------
A NOTE ON LARGE REDEMPTIONS

It is important that you call Vanguard  before you redeem a large dollar amount.
It is our responsibility to consider the interests of all fund shareholders, and
so we reserve the right to delay  delivery of your  redemption  proceeds--up  to
seven days--if the amount may disrupt the Fund's operation or performance.
     If you redeem more than  $250,000  worth of Fund  shares  within any 90-day
period,  the  Fund  reserves  the  right  to pay  part or all of the  redemption
proceeds above $250,000  in-kind,  i.e., in securities,  rather than in cash. If
payment is made in-kind,  you may incur  brokerage  commissions  if you elect to
sell the securities for cash.

- --------------------------------------------------------------------------------
OPTIONS FOR REDEMPTION PROCEEDS
You may receive  your  redemption  proceeds in one of three  ways:  check,  wire
(money market funds and other daily dividend funds only), or exchange to another
Vanguard fund.
- --------------------------------------------------------------------------------
CHECK REDEMPTIONS
Normally,  Vanguard  will  mail  your  check  within  two  business  days  of  a
redemption.
- --------------------------------------------------------------------------------
WIRE REDEMPTIONS [WIRE]
The wire redemption option is not automatic; you must establish it by completing
a special  form or the  appropriate  section of your account  application.  Wire
redemptions can be initiated by mail or by telephone during Vanguard's  business
hours, but not online.

For Money Market Funds:

For telephone  requests made by 10:30 a.m. Eastern time, the wire will arrive at
your  bank by the close of  business  that  same  day.  Requests  made by 4 p.m.
Eastern time will arrive at your bank by the close of business on the  following
business day.

For Other Daily Dividend Funds:
For telephone requests made by 4 p.m. Eastern time, the wire will arrive at your
bank by the close of business on the following business day.

- --------------------------------------------------------------------------------
NOTE: Wire redemptions of less than $5,000 are subject to a $5 processing fee.
- --------------------------------------------------------------------------------
EXCHANGE REDEMPTIONS
As described  above, an exchange  involves using the proceeds of your redemption
to purchase shares of another Vanguard fund.
- --------------------------------------------------------------------------------

FOR OUR MUTUAL PROTECTION
For your best interests and ours, Vanguard applies these additional requirements
to redemptions:

REQUEST IN "GOOD ORDER"
All redemption requests must be received by Vanguard in "good order." This means
that your request must include:
- -    The Fund name and account number.
- -    The amount of the transaction (in dollars or shares).
- -    Signatures  of all owners  exactly as  registered  on the account (for mail
     requests).

<PAGE>

17

- -    Signature guarantees (if required).*
- -    Any supporting legal documentation that may be required.
- -    Any outstanding certificates representing shares to be redeemed.

*For instance,  a signature guarantee must be provided by all registered account
 shareholders  when redemption  proceeds are to be sent to a different person or
 address. A signature guarantee can be obtained from most commercial and savings
 banks,  credit  unions,  trust  companies,  or  member  firms  of a U.S.  stock
 exchange.

TRANSACTIONS ARE PROCESSED AT THE NEXT-DETERMINED SHARE PRICE AFTER VANGUARD HAS
RECEIVED ALL REQUIRED INFORMATION.
- --------------------------------------------------------------------------------

ALL TRADES ARE FINAL
Vanguard  will not cancel any  transaction  request  (including  any purchase or
redemption)  that we believe to be authentic once the request has been initiated
and a confirmation number assigned.
- --------------------------------------------------------------------------------
UNCASHED CHECKS
Please cash your distribution or redemption  checks promptly.  Vanguard will not
pay interest on uncashed checks.
- --------------------------------------------------------------------------------


TRANSFERRING REGISTRATION

You can  transfer  the  registration  of your Fund  shares to  another  owner by
completing a transfer form and sending it to Vanguard.

First-class mail to:         Express or Registered mail to:
The Vanguard Group           The Vanguard Group
P.O. Box 2900                100 Vanguard Boulevard
Valley Forge, PA 19482-2900  Malvern, PA 19355-2331
- --------------------------------------------------------------------------------


FUND AND ACCOUNT UPDATES

STATEMENTS AND REPORTS
We will send you account and tax  statements to help you keep track of your Fund
account  throughout  the year as well as when you are preparing  your income tax
returns.

     In addition,  you will  receive  financial  reports  about the Fund twice a
year.  These   comprehensive   reports  include  an  assessment  of  the  Fund's
performance  (and a comparison  to its industry  benchmark),  an overview of the
financial  markets,  a  report  from  the  adviser,  and  the  Fund's  financial
statements which include a listing of the Fund's holdings.

     To keep  the  Fund's  costs  as low as  possible  (so  that  you and  other
shareholders can keep more of the Fund's investment earnings), Vanguard attempts
to  eliminate  duplicate  mailings  to the same  address.  When two or more Fund
shareholders  have the same last name and address,  we send just one Fund report
to that address--instead of mailing separate reports to each shareholder. If you
want  us  to  send  separate  reports,  notify  our  Institutional  Division  at
1-888-809-8102.
- --------------------------------------------------------------------------------
CONFIRMATION STATEMENT
Sent each time you buy,  sell, or exchange  shares;  confirms the trade date and
the amount of your transaction.
- --------------------------------------------------------------------------------

<PAGE>

18

- --------------------------------------------------------------------------------
PORTFOLIO SUMMARY [BOOK]
Mailed  quarterly for most  accounts;  shows the market value of your account at
the close of the statement period, as well as distributions,  purchases,  sales,
and exchanges for the current calendar year.
- --------------------------------------------------------------------------------
FUND FINANCIAL REPORTS
Mailed in January and July for this Fund.
- --------------------------------------------------------------------------------
TAX STATEMENTS
Generally mailed in January; report previous year's dividend distributions,  and
proceeds from the sale of shares.
- --------------------------------------------------------------------------------


MANDATORY CONVERSION TO INVESTOR SHARES

The Fund reserves the right to convert an investor's  Institutional  Shares into
Investor  Shares of the Fund if the investor's  account  balance falls below $10
million. Any such conversion will be preceded by written notice to the investor.
- --------------------------------------------------------------------------------

<PAGE>

                     (THIS PAGE INTENTIONALLY LEFT BLANK.)

<PAGE>

                     (THIS PAGE INTENTIONALLY LEFT BLANK.)

<PAGE>

GLOSSARY OF INVESTMENT TERMS

DIVIDEND INCOME
Payment to  shareholders  of income from  interest or  dividends  generated by a
fund's investments.

EXPENSE RATIO
The  percentage  of a fund's  average net assets used to pay its  expenses.  The
expense ratio  includes  management  fees,  administrative  fees,  and any 12b-1
distribution fees.

INVESTMENT ADVISER
An  organization  that  makes  the  day-to-day   decisions  regarding  a  fund's
investments.

LIQUIDITY
The degree of a security's  marketability (that is, how quickly the security can
be sold at a fair price and converted to cash).

MONEY MARKET FUND
A mutual fund that seeks to provide income,  liquidity, and a stable share price
by investing in very short-term, liquid investments.

MONEY MARKET INSTRUMENTS
Short-term,  liquid  investments (usually with a maturity of 13 months or less),
which  include  U.S.   Treasury  bills,  bank  certificates  of  deposit  (CDs),
repurchase agreements, commercial paper, and banker's acceptances.

MUTUAL FUND
An  investment  company  that pools the money of many people and invests it in a
variety of securities in an effort to achieve a specific objective over time.

NET ASSET VALUE (NAV)
The market value of a mutual fund's total assets, minus liabilities,  divided by
the  number of shares  outstanding.  The value of a single  share is called  its
share value or share price.

PRINCIPAL
The amount of money you put into an investment.

SECURITIES
Stocks,  bonds,  money market  instruments,  and  interests in other  investment
vehicles.

TOTAL RETURN
A percentage change,  over a specified time period, in a mutual fund's net asset
value,  with the ending net asset value adjusted to account for the reinvestment
of all distributions of dividends and capital gains.

VOLATILITY
The  fluctuations  in value of a mutual  fund or other  security.  The greater a
fund's volatility, the wider the fluctuations between its high and low prices.

YIELD
Income  (interest  or  dividends)  earned  by  an  investment,  expressed  as  a
percentage of the investment's price.

<PAGE>


                                                    [SHIP(R) LOGO]
                                                    [THE VANGUARD GROUP(R) LOGO]

                                                    Institutional Division
                                                    Post Office Box 2900
                                                    Valley Forge, PA 19482-2900

FOR MORE INFORMATION
If you'd like more information about
Vanguard Prime Money Market
Fund Institutional Shares, the
following documents are available
free upon request:

ANNUAL/SEMIANNUAL REPORTS
TO SHAREHOLDERS
Additional information about the
Fund's investments is available in
the Vanguard Money Market Funds'
annual and semiannual reports
to shareholders.

STATEMENT OF ADDITIONAL
INFORMATION (SAI)
The SAI (for Vanguard Money
Market Funds) provides more
detailed information about the Fund.

The current annual and semiannual
reports and the SAI are
incorporated by reference into
(and are thus legally a part of)
this prospectus.

To receive a free copy of the latest
annual or semiannual report or the
SAI, or to request additional
information about the Fund or other
Vanguard funds, please contact us
as follows:

If you are an Individual Investor:
THE VANGUARD GROUP
INVESTOR INFORMATION DEPARTMENT
P.O. BOX 2600
VALLEY FORGE, PA 19482-2600

TELEPHONE:
1-800-662-7447 (SHIP)

TEXT TELEPHONE:
1-800-952-3335

If you are a client of Vanguard's
Institutional Division:
THE VANGUARD GROUP
INSTITUTIONAL INVESTOR
INFORMATION
P.O. BOX 2900
VALLEY FORGE, PA 19482-2900

TELEPHONE:
1-888-809-8102

WORLD WIDE WEB:
WWW.VANGUARD.COM

If you are a current Fund shareholder
and would like information about
your account, account transactions,
and/or account statements,
please call:

CLIENT SERVICES DEPARTMENT
TELEPHONE:
1-800-662-2739 (CREW)

TEXT TELEPHONE:
1-800-749-7273

INFORMATION PROVIDED BY THE
SECURITIES AND EXCHANGE
COMMISSION (SEC)
You can review and copy
information about the Fund
(including the SAI) at the SEC's
Public Reference Room in
Washington, DC. To find out more
about this public service, call the
SEC at 1-800-SEC-0330. Reports and
other information about the Fund are
also available on the SEC's website
(www.sec.gov), or you can receive
copies of this information, for a fee,
by writing the Public Reference
Section, Securities and Exchange
Commission, Washington, DC
20549-6009.

Fund's Investment Company Act file
number: 811-2554

(C) 2000 The Vanguard Group, Inc.
All rights reserved.
Vanguard Marketing Corporation,
Distributor.

I066N-03/24/2000


<PAGE>

                                     PART B


                        VANGUARD(R) MONEY MARKET RESERVES
                             VANGUARD TREASURY FUND

                 (ALSO KNOWN AS THE VANGUARD MONEY MARKET FUNDS)
               (INDIVIDUALLY THE TRUST; COLLECTIVELY THE TRUSTS)

                       STATEMENT OF ADDITIONAL INFORMATION
                                 MARCH 24, 2000

     This Statement is not a prospectus  but should be read in conjunction  with
the Trusts'  current  Prospectus  (dated  March 24,  2000).  To obtain,  without
charge,  the Prospectus or the most recent Annual Report to Shareholders,  which
contains the Funds'  financial  statements as hereby  incorporated by reference,
please call the Investor Information Department:


                        INVESTOR INFORMATION DEPARTMENT
                                  1-800-662-7447

                               TABLE OF CONTENTS

                                                                            PAGE
                                                                            ----
DESCRIPTION OF THE FUNDS.....................................................B-1
INVESTMENT POLICIES..........................................................B-3
FUNDAMENTAL INVESTMENT LIMITATIONS...........................................B-4
CALCULATION OF TOTAL RETURN..................................................B-5
CALCULATION OF YIELD.........................................................B-6
SHARE PRICE..................................................................B-7
PURCHASE OF SHARES...........................................................B-8
REDEMPTION OF SHARES.........................................................B-8
MANAGEMENT OF THE FUNDS......................................................B-8
FINANCIAL STATEMENTS........................................................B-12
DESCRIPTION OF SECURITIES AND RATINGS.......................................B-12
COMPARATIVE INDEXES.........................................................B-14

                            DESCRIPTION OF THE FUNDS

ORGANIZATION

     Vanguard  Money  Market  Reserves was  organized as Whitehall  Money Market
Trust  in  1974  before  becoming  a  Maryland  corporation  in  1985.  It  then
reorganized  as  a  Delaware   business  trust  in  May,  1998.   Prior  to  its
reorganization  as a Delaware  business  trust,  the Trust was known as Vanguard
Money Market Reserves,  Inc.  Vanguard Treasury Fund was organized as a Delaware
business trust in August, 1996. Prior to its organization as a Delaware business
trust,  the Trust  operated as the U.S.  Treasury  Portfolio  of Vanguard  Money
Market Reserves.  Each Trust is registered with the United States Securities and
Exchange  Commission (the Commission)  under the Investment  Company Act of 1940
(the 1940 Act) as an open-end,  diversified  management  investment company. The
Trusts currently offer the following Funds and classes of shares:

                         VANGUARD MONEY MARKET RESERVES

   Vanguard Prime Money Market Fund: Investor Shares and Institutional Shares

           Vanguard Federal Money Market Fund (Investor Shares only)

                             VANGUARD TREASURY FUND

           Vanguard Treasury Money Market Fund (Investor Shares only)

               (individually, the Fund; collectively, the Funds)

                                      B-1
<PAGE>


     Each Trust has the ability to offer  additional funds or classes of shares.
There is no limit on the number of full and  fractional  shares that a Trust may
issue for a single fund or class of shares.

SERVICE PROVIDERS

     CUSTODIAN.  The Bank of New York,  One Wall  Street,  New  York,  NY 10286,
serves as the Funds' custodian. The custodian is responsible for maintaining the
Funds' assets and keeping all necessary accounts and records of Fund assets.

     INDEPENDENT ACCOUNTANTS.  PricewaterhouseCoopers LLP, 30 South 17th Street,
Philadelphia,  Pennsylvania 19103, serves as the Funds' independent accountants.
The accountants audit the Funds' financial  statements and provide other related
services.

     TRANSFER  AND   DIVIDEND-PAYING   AGENT.  The  Funds'  transfer  agent  and
dividend-paying  agent is The Vanguard  Group,  Inc.,  100  Vanguard  Boulevard,
Malvern, Pennsylvania 19355.

CHARACTERISTICS OF THE FUNDS' SHARES

     RESTRICTIONS  ON HOLDING OR DISPOSING OF SHARES.  There are no restrictions
on the right of  shareholders  to retain or dispose of the Funds' shares,  other
than the  possible  future  termination  of either of the Trusts or any of their
Funds. The Funds may be terminated by reorganization into another mutual fund or
by  liquidation  and  distribution  of the assets of the affected  fund.  Unless
terminated  by   reorganization   or   liquidation,   the  Funds  will  continue
indefinitely.

     SHAREHOLDER  LIABILITY.  The Funds are organized  under Delaware law, which
provides  that  shareholders  of a  business  trust  are  entitled  to the  same
limitations of personal  liability as  shareholders  of a corporation  organized
under  Delaware law.  Effectively,  this means that a shareholder of a Fund will
not be personally liable for payment of the Fund's debts except by reason of his
or her own conduct or acts. In addition,  a shareholder  could incur a financial
loss on account of a Fund  obligation  only if the Fund itself had no  remaining
assets with which to meet such  obligation.  We believe that the  possibility of
such a situation arising is extremely remote.

     DIVIDEND  RIGHTS.  The  shareholders  of a fund are entitled to receive any
dividends or other distributions declared for such fund. No shares have priority
or  preference  over  any  other  shares  of  the  same  fund  with  respect  to
distributions. Distributions will be made from the assets of a fund, and will be
paid ratably to all  shareholders of the fund (or class) according to the number
of shares of such fund (or class) held by  shareholders  on the record date. The
amount of income  dividends per share may vary between separate share classes of
the same fund based upon  differences  in the way that  expenses  are  allocated
between share classes pursuant to a multiple class plan.

     VOTING  RIGHTS.  Shareholders  are  entitled  to vote on a matter if: (i) a
shareholder  vote is required  under the 1940 Act;  (ii) the matter  concerns an
amendment to the Declaration of Trust that would adversely  affect to a material
degree the rights and  preferences  of the shares of any class or fund; or (iii)
the Trustees determine that it is necessary or desirable to obtain a shareholder
vote.  The 1940 Act requires a  shareholder  vote under  various  circumstances,
including to elect or remove  Trustees upon the written  request of shareholders
representing  10% or more of a Fund's net assets,  and to change any fundamental
policy of the Fund.  Shareholders  of the Funds receive one vote for each dollar
of net asset  value owned on the record  date,  and a  fractional  vote for each
fractional dollar of net asset value owned on the record date. However, only the
shares of the fund affected by a particular  matter are entitled to vote on that
matter.  Voting  rights  are  noncumulative  and  cannot be  modified  without a
majority vote.

     LIQUIDATION  RIGHTS.  In the  event of  liquidation,  shareholders  will be
entitled to receive a pro rata share of the net assets of the applicable Fund.

     PREEMPTIVE RIGHTS. There are no preemptive rights associated with shares of
the Funds.

     CONVERSION RIGHTS.  Shareholders of the Funds may convert their shares into
another  class of shares of the same  series upon the  satisfaction  of any then
applicable eligibility requirements.

     REDEMPTION  PROVISIONS.  The Funds' redemption  provisions are described in
their  current  prospectuses  and  elsewhere  in this  Statement  of  Additional
Information.


                                      B-2
<PAGE>


     SINKING FUND PROVISIONS. The Funds have no sinking fund provisions.

     CALLS OR  ASSESSMENT.  The Funds' shares,  when issued,  are fully paid and
non-assessable.

TAX STATUS OF THE FUNDS

     Each Fund  intends  to  continue  to  qualify  as a  "regulated  investment
company"  under  Subchapter M of the  Internal  Revenue  Code.  This special tax
status  means  that a fund  will not be liable  for  federal  tax on income  and
capital gains distributed to shareholders.  In order to preserve its tax status,
a fund must  comply  with  certain  requirements.  If a fund fails to meet these
requirements  in any  taxable  year,  it will be subject  to tax on its  taxable
income at corporate  rates,  and all  distributions  from  earnings and profits,
including any  distributions of net tax-exempt  income and net long-term capital
gains, will be taxable to shareholders as ordinary income.  In addition,  a fund
could be required to  recognize  unrealized  gains,  pay  substantial  taxes and
interest, and make substantial  distributions before regaining its tax status as
a regulated investment company.

                              INVESTMENT POLICIES

     The following policies supplement the investment objective and policies set
forth in the Funds' Prospectus:

     REPURCHASE AGREEMENTS.  The Prime and Federal Money Market Funds may invest
in repurchase  agreements with commercial  banks,  brokers or dealers either for
defensive  purposes due to market  conditions  or to generate  income from their
excess cash  balances.  A repurchase  agreement is an agreement  under which the
Fund acquires a fixed-income  security  (generally a security issued by the U.S.
Government or an agency  thereof,  a banker's  acceptance  or a  certificate  of
deposit)  from a  commercial  bank,  broker or dealer,  subject to resale to the
seller at an agreed upon price and date  (normally,  the next  business  day). A
repurchase agreement may be considered a loan collateralized by securities.  The
resale price  reflects an agreed upon interest rate effective for the period the
instrument  is held by the Fund and is  unrelated  to the  interest  rate on the
underlying  instrument.  In these  transactions,  the securities acquired by the
Fund  (including  accrued  interest  earned  thereon) must have a total value in
excess of the value of the repurchase agreement and are held by a custodian bank
until  repurchased.  In addition,  the Funds'  Board of Trustees  will monitor a
Fund's repurchase agreement transactions generally and will establish guidelines
and standards for review by the investment  adviser of the  creditworthiness  of
any bank, broker or dealer party to a repurchase agreement with the Fund.

     The use of repurchase  agreements  involves certain risks. For example,  if
the other party to the agreement  defaults on its  obligation to repurchase  the
underlying  security at a time when the value of the security has declined,  the
Fund may incur a loss upon  disposition  of the security.  If the other party to
the agreement  becomes  insolvent and subject to liquidation  or  reorganization
under  bankruptcy  or other  laws,  a court may  determine  that the  underlying
security is collateral for a loan by the Fund not within the control of the Fund
and therefore the realization by the Fund on such collateral may be indefinitely
delayed.  Finally,  it is possible that the Fund may not be able to substantiate
its interest in the underlying  security and may be deemed an unsecured creditor
of the other party to the agreement. While the adviser acknowledges these risks,
it  is  expected  that  they  can  be  controlled   through  careful  monitoring
procedures.

     LENDING OF  SECURITIES.  Each Fund may lend its  investment  securities  to
qualified  institutional  investors (typically brokers,  dealers, banks or other
financial  institutions)  who need to  borrow  securities  in order to  complete
certain transactions, such as covering short sales, avoiding failures to deliver
securities  or  completing  arbitrage  operations.  By  lending  its  investment
securities,  a Fund attempts to increase its net  investment  income through the
receipt of  interest  on the loan.  Any gain or loss in the market  price of the
securities  loaned that might occur during the term of the loan would be for the
account of the Fund.  The terms and the structure  and the  aggregate  amount of
such loans must be consistent  with the 1940 Act, and the Rules and  Regulations
or  interpretations  of the Commission  thereunder.  These  provisions limit the
amount of securities a fund may lend to 33 1/3% of the Fund's total assets,  and
require  that (a) the  borrower  pledge and  maintain  with the Fund  collateral
consisting of cash,  an  irrevocable  letter of credit or  securities  issued or
guaranteed  by the United  States  Government  having at all times not less than
100%  of the  value  of the  securities  loaned,  (b) the  borrower  add to such
collateral whenever the price of the securities loaned rises (i.e., the borrower
"marks  to the  market"  on a daily  basis),  (c) the  loan be made  subject  to
termination  by the  Fund  at any  time,  and (d) the  Fund  receive  reasonable
interest on the loan (which may include the Fund's investing any cash collateral
in interest bearing


                                      B-3
<PAGE>


short-term  investments),  any  distribution  on the loaned  securities  and any
increase in their market value.  Loan  arrangements made by the Fund will comply
with all other applicable  regulatory  requirements,  including the rules of the
New York Stock Exchange,  which presently require the borrower, after notice, to
redeliver the  securities  within the normal  settlement  time of three business
days. All relevant facts and circumstances,  including the  creditworthiness  of
the broker,  dealer or institution,  will be considered in making decisions with
respect to the lending of  securities,  subject to review by the Funds' Board of
Trustees.

     VANGUARD INTERFUND LENDING PROGRAM.  The Commission has issued an exemptive
order  permitting  the Funds to  participate  in  Vanguard's  interfund  lending
program.  This program  allows the Vanguard  funds to borrow money from and loan
money to each other for temporary or emergency purposes.  The program is subject
to a number of conditions,  including the requirement that no fund may borrow or
lend money through the program unless it receives a more favorable interest rate
than is available from a typical bank for a comparable transaction. In addition,
a fund may  participate  in the  program  only if and to the  extent  that  such
participation  is  consistent  with the fund's  investment  objective  and other
investment  policies.   The  Boards  of  Trustees  of  the  Vanguard  funds  are
responsible  for  ensuring  that  the  interfund  lending  program  operates  in
compliance with all conditions of the Commission's exemptive order.

     ILLIQUID  SECURITIES.  Each Fund may  invest up to 10% of its net assets in
illiquid securities.  Illiquid securities are securities that may not be sold or
disposed of in the ordinary  course of business  within seven  business  days at
approximately the value at which they are being carried on the Fund's books.

     Each Fund may invest in restricted, privately placed securities that, under
securities  laws, may be sold only to qualified  institutional  buyers.  Because
these securities can be resold only to qualified  institutional buyers, they may
be considered illiquid securities---meaning that they could be difficult for the
Fund to convert to cash if needed.

     If a substantial market develops for a restricted  security held by a Fund,
it will be treated as a liquid  security,  in  accordance  with  procedures  and
guidelines  approved by the Fund's Board of Trustees.  This  generally  includes
securities  that are  unregistered  that can be sold to qualified  institutional
buyers in accordance with Rule 144A under the Securities Act of 1933.  While the
Funds' investment adviser determines the liquidity of restricted securities on a
daily basis,  the Board  oversees and retains  ultimate  responsibility  for the
adviser's  decisions.  Several  factors that the Board  considers in  monitoring
these  decisions  include the  valuation  of a  security,  the  availability  of
qualified  institutional  buyers,  and the availability of information about the
security's issuer.


                       FUNDAMENTAL INVESTMENT LIMITATIONS

     Each Fund is subject to the following fundamental  investment  limitations,
which  cannot be changed in any material way without the approval of the holders
of a majority of the affected Fund's shares. For these purposes, a "majority" of
shares  means  shares  representing  the lesser of: (i) 67% or more of the votes
cast to approve a change,  so long as shares  representing  more than 50% of the
Fund's net asset value are present or  represented  by proxy;  or (ii) more than
50% of the Fund's net asset value.

     BORROWING. The Fund may not borrow money, except for temporary or emergency
purposes in an amount not exceeding  15% of the Fund's net assets.  The Fund may
borrow money through banks,  reverse  repurchase  agreements  (Prime and Federal
Money Market Funds only), or Vanguard's interfund lending program only, and must
comply with all  applicable  regulatory  conditions.  The Fund may not borrow to
increase income (leveraging),  but only to facilitate  redemption requests which
might otherwise  require  untimely  dispositions of portfolio  securities.  When
borrowing  exceeds  5% of the  Fund's  net  assets,  the  Fund  will  repay  all
borrowings  before  making  additional  investments,  and interest  paid on such
borrowings will reduce net income.

     COMMODITIES. The Fund may not invest in commodities or commodity contracts.

     DIVERSIFICATION.  The Fund may not purchase securities of any issuer if, as
a result,  more than 5% of the Fund's  total  assets  would be  invested in that
issuer's securities. This limitation does not apply to obligations of the United
States Government,  its agencies, or  instrumentalities.  The Fund may, however,
invest in a single  issuer  as  permitted  by the  Commission  (which  currently
permits a money  market  fund to  invest  up to 25% of its  total  assets in the
highest-quality  securities  of a  single  issuer  for a  period  of up to three
business days).


                                      B-4
<PAGE>

     ILLIQUID SECURITIES. The Fund may not acquire any security if, as a result,
more  than  10% of its net  assets  would be  invested  in  securities  that are
illiquid.

     INDUSTRY CONCENTRATION.  The Fund may not invest more than 25% of its total
assets in any one industry, provided that there is no limitation with respect to
investments  in  United  States  Treasury  Bills,  other  obligations  issued or
guaranteed  by the Federal  Government,  its agencies and  instrumentalities  or
certificates of deposit or banker's acceptances of domestic institutions.

     INVESTING FOR CONTROL. The Fund may not invest in a company for purposes of
controlling its management.

     INVESTMENT  COMPANIES.  The Fund may not  invest  in any  other  investment
company, except through a merger,  consolidation or acquisition of assets, or to
the extent permitted by Section 12 of the 1940 Act.  Investment  companies whose
shares the Fund acquires pursuant to Section 12 must have investment  objectives
and investment policies consistent with those of the Fund.

     LOANS. The Fund may not make loans to other persons, except by the purchase
of obligations in which the Fund is authorized to invest, or through  Vanguard's
interfund lending program;  provided,  however, that the Fund may not enter into
repurchase  agreements if, as a result thereof,  more than 10% of the net assets
of any Fund (taken at current  value) would be subject to repurchase  agreements
maturing in more than seven days.

     MARGIN.  The Fund may not purchase  securities on margin or sell securities
short.

     OIL,  GAS,  MINERALS.  The Fund may not invest in  interests in oil, gas or
other mineral exploration or development programs.

     PLEDGING ASSETS. The Fund may pledge, mortgage or hypothecate its assets in
an  amount  up to 15% of its net  assets,  but  only to  secure  borrowings  for
temporary or emergency purposes.

     PUT, CALL,  STRADDLE,  SPREAD OPTIONS.  The Fund may not write or invest in
put, call, straddle, or spread options.

     REAL  ESTATE.  The Fund may not invest  directly  in real  estate,  or real
estate investment trust securities.

     SENIOR  SECURITIES.  The Fund may not issue  senior  securities,  except in
compliance with the 1940 Act.

     UNDERWRITING.  The Fund may not  engage  in the  business  of  underwriting
securities  issued  by  other  persons.  The  Fund  will  not be  considered  an
underwriter when disposing of its investment securities.

     The above  mentioned  investment  limitations  are  considered  at the time
investment securities are purchased.

     None  of  these  limitations  prevents  a Fund  from  participating  in The
Vanguard  Group  (Vanguard).  Because  the Funds are a member of the Group,  the
Funds may own  securities  issued  by  Vanguard,  make  loans to  Vanguard,  and
contribute to Vanguard's costs or other financial  requirement.  See "Management
of the Funds" for more information.

                          CALCULATION OF TOTAL RETURN





     The  average  annual  total  return of each Fund for the one-,  five-,  and
ten-year periods ended November 30, 1999 is set forth below:

                             ONE YEAR ENDED   FIVE YEARS ENDED   TEN YEARS ENDED
    FUND                       11/30/1999        11/30/1999        11/30/1999
    ----                       ----------        ----------        ----------
    Prime Money Market
    Fund Investor Shares          4.97%             5.39%             5.24%
    Prime Money Market
    Fund Institutional
    Shares*                       5.15%             5.57%             5.40%**
    Federal Money Market
    Fund                          4.89%             5.33%             5.15%
    Treasury Money Market
    Fund                          4.51%             5.05%             4.93%
- ---------
 *Prior to October 28, 1995, total returns are for Vanguard Institutional Money
  Market Portfolio.
**Since inception of Vanguard Institutional Money Market Portfolio on October 3,
  1989.


                                      B-5
<PAGE>



AVERAGE ANNUAL TOTAL RETURN

Average annual total return is the average annual  compounded rate of return for
the periods of one year,  five years,  ten years, or the life of each Portfolio,
all  ended on the  last  day of a recent  month.  Average  annual  total  return
quotations  will  reflect  changes  in the price of the  Portfolios'  shares and
assume that all dividends and capital gains distributions  during the respective
periods were  reinvested  in Portfolio  shares.  Average  annual total return is
calculated  by  finding  the  average  annual  compounded  rates of  return of a
hypothetical  investment  over such periods  according to the following  formula
(average annual total return is then expressed as a percentage):

                               T = (ERV/P)1/N - 1

  Where:

          T   =average annual total return
          P   =a hypothetical initial investment of $1,000
          n   =number of years
          ERV =ending redeemable value: ERV is the value, at the end
               of the applicable period, of a hypothetical $1,000
               investment made at the beginning of the applicable
               period.

CUMULATIVE TOTAL RETURN

Cumulative  total  return is the  cumulative  rate of  return on a  hypothetical
initial  investment of $1,000 for a specified  period.  Cumulative  total return
quotations  reflect changes in the price of each  Portfolios'  shares and assume
that all  dividends  and  capital  gains  distributions  during the period  were
reinvested in Portfolio shares. Cumulative total return is calculated by finding
the cumulative rates of a return of a hypothetical investment over such periods,
according to the following formula (cumulative total return is then expressed as
a percentage):

                                C = (ERV/P) - 1

  Where:

          C   =cumulative total return
          P   =a hypothetical initial investment of $1,000
          ERV =ending redeemable value: ERV is the value, at the end
               of the applicable period, of a hypothetical $1,000
               investment made at the beginning of the applicable
               period.

                              CALCULATION OF YIELD

     The current yield of each Fund is calculated  daily on a base period return
of a  hypothetical  account  having  a  beginning  balance  of one  share  for a
particular  period of time  (generally  7 days).  The  return is  determined  by
dividing the net change  (exclusive  of any capital  changes) in such account by
its average net asset value for the period,  and then multiplying it by 365/7 to
get the annualized  current yield.  The  calculation of net change  reflects the
value of additional  shares purchased with the dividends by the Fund,  including
dividends on both the original share and on such additional shares. An effective
yield, which reflects the effects of compounding and represents an annualization
of the current yield with all dividends  reinvested,  may also be calculated for
the Fund by adding 1 to the net change,  raising the sum to the 365/7 power, and
subtracting 1 from the result.

     Set forth below is an example,  for purposes of  illustration  only, of the
current and  effective  yield  calculations  for each of the Funds for the 7-day
base period ended November 30, 1999.


                                      B-6
<PAGE>


                                            PRIME MONEY         PRIME MONEY
                                            MARKET FUND         MARKET FUND
                                          INVESTOR SHARES   INSTITUTIONAL SHARES
                                             11/30/1999          11/30/1999
                                             ----------          ----------
      Value of account at beginning
       of period. . . . . . . . . . . . .     $1.00000            $1.00000
      Value of same account at end of
       period*. . . . . . . . . . . . . .      1.00103             1.00106
                                              --------            --------
      Net change in account value . . . .     $ .00103            $ .00106

      Annualized current net yield
      (Net change X 365/7)
       -/- average net asset value. . . .        5.36%               5.54%
                                                 =====               =====
      Effective Yield
       [(Net change) + 1]365/7 - 1. . . .        5.50%               5.66%
                                                 =====               =====
      Average weighted maturity of
       investments. . . . . . . . . . . .      69 days             69 days
                                               =======             =======
- ---------
* Exclusive of any capital changes and income other than investment income.

                                           FEDERAL MONEY       TREASURY MONEY
                                            MARKET FUND         MARKET FUND
                                             11/30/1999          11/30/1999
                                             ----------          ----------
      Value of account at beginning
       of period. . . . . . . . . . . . .     $1.00000            $1.00000
      Value of same account at end of
       period*. . . . . . . . . . . . . .      1.00100             1.00092
                                              --------            --------
      Net change in account value . . . .     $ .00100            $ .00092

      Annualized current net yield
      (Net change X 365/7)
       -/- average net asset value. . . .        5.21%               4.77%
                                                 =====               =====
      Effective Yield
       [(Net change) + 1]365/7 - 1. . . .        5.33%               4.90%
                                                 =====               =====
      Average weighted maturity of
       investments. . . . . . . . . . . .      70 days             77 days
                                               =======             =======
- ---------
* Exclusive of any capital changes and income other than investment income.

     Each Fund seeks to maintain,  but does not guarantee,  a constant net asset
value of $1.00.  The yield of each Fund will fluctuate.  The Funds have obtained
private  insurance that  partially  protects the Prime Money Market Fund against
default of  principal  or interest  payments on the  instruments  it holds,  and
against  bankruptcy  by  issuers  and  credit  enhancers  of these  instruments.
Treasury and other U.S. Government securities held by the Fund are excluded from
this coverage. The annualization of a week's dividend is not a representation by
the Fund as to what an investment in the Fund will actually yield in the future.
Actual  yields will depend on such  variables  as  investment  quality,  average
maturity, the type of instruments the Fund invests in, changes in interest rates
on instruments,  changes in the expenses of the Funds and other factors.  Yields
are one basis  investors  may use to  analyze  the Funds,  and other  investment
vehicles;  however,  yields of other  investment  vehicles may not be comparable
because of the factors set forth in the preceding  sentence,  differences in the
time periods compared,  and differences in the methods used in valuing portfolio
instruments, computing net asset values and calculating yields.


                                  SHARE PRICE


     Each Fund's share price,  or "net asset value" per share,  is calculated by
dividing the total assets of the Fund, less all liabilities, by the total number
of shares outstanding,  except for the Prime Money Market Fund whereby net asset
value is calculated by dividing the net assets attributed to each share class by
the total number of shares outstanding for that share class. The net asset value
is determined as of the close of regular  trading on the New York Stock Exchange
(generally 4:00 p.m. Eastern time) on each day the Exchange is open for trading.

     It is the policy of each Fund to attempt to  maintain a net asset  value of
$1.00 per share for sales and redemptions.  The instruments held by the Fund are
valued  on the  basis of  amortized  cost,  which  does not  take  into  account
unrealized  capital gains or losses.  This involves valuing an instrument at its
cost and thereafter assuming a constant amortization to maturity of any discount
or premium, regardless of the impact of fluctuating interest rates on the market
value of the instrument. While this method provides certainty in

                                      B-7
<PAGE>

valuation,  it may  result in periods  during  which  value,  as  determined  by
amortized  cost,  is higher or lower than the price which the Fund would receive
if it sold the  instrument.  Such procedures will include a review of the Funds'
holdings by the Trustees,  at such  intervals as they may deem  appropriate,  to
determine  whether  the Funds' net asset  value  calculated  by using  available
market  quotations  deviates from $1.00 per share based on amortized  cost.  The
extent of any  deviation  will be examined by the  Trustees.  If such  deviation
exceeds 1/2 of 1%, the Trustees will promptly consider what action, if any, will
be initiated.  In the event the Trustees determine that a deviation exists which
may result in material dilution or other unfair results to investors or existing
shareholders,  they have agreed to take such corrective action as they regard as
necessary  and  appropriate,  including  the sale of fund  instruments  prior to
maturity to realize capital gains or losses or to shorten average fund maturity;
withholding  dividends;  making a special capital  distribution;  redemptions of
shares in kind; or  establishing a net asset value per share by using  available
market quotations.

     The use of amortized cost and the maintenance of the Fund's net asset value
at $1.00 is based on its election to operate under Rule 2a-7 under the 1940 Act.
As a  condition  of  operating  under  that  rule,  the  Fund  must  maintain  a
dollar-weighted  average  portfolio  maturity of 90 days or less,  purchase only
instruments having remaining  maturities of 397 days or less, and invest only in
securities  that are  determined by methods  approved by the Trustees to present
minimal credit risks and that are of high quality as determined by the requisite
rating  services,  or in the case of an instrument  not so rated,  determined by
methods approved by the Trustees to be of comparable quality.

                               PURCHASE OF SHARES

     Each Fund  reserves  the right in its sole  discretion  (i) to suspend  the
offerings of its shares,  (ii) to reject purchase orders when in the judgment of
management  such  rejection  is in the best  interest of the Fund,  and (iii) to
reduce or waive the minimum  investment for or any other restrictions on initial
and subsequent investments for certain fiduciary accounts or under circumstances
where certain economies can be achieved in sales of the Fund's shares.

                              REDEMPTION OF SHARES

     Each Fund may suspend redemption privileges or postpone the date of payment
(i) during any period that the New York Stock Exchange is closed,  or trading on
the Exchange is  restricted as  determined  by the  Commission,  (ii) during any
period  when an  emergency  exists as defined by the  Commission  as a result of
which it is not reasonably practicable for a Fund to dispose of securities owned
by it, or fairly to determine the value of its assets,  and (iii) for such other
periods as the Commission may permit.

     Each  Fund has made an  election  with  the  Commission  to pay in cash all
redemptions  requested by any shareholder of record limited in amount during any
90-day  period to the lesser of  $250,000 or 1% of the net assets of the Fund at
the beginning of such period.

     No charge is made by a Fund for redemptions; except for wire withdrawals in
amounts  less than  $5,000  which will be subject to a maximum  charge of $5.00.
Shares redeemed may be worth more or less than what was paid for them, depending
on the market value of the securities held by each Fund.




                             MANAGEMENT OF THE FUNDS

OFFICERS AND TRUSTEES

     The  officers  of  each  Fund  manage  its  day-to-day  operations  and are
responsible to the Fund's Board of Trustees. The Trustees set broad policies for
the Funds and choose their officers. The following is a list of the Trustees and
officers of the Funds and a statement of their  present  positions and principal
occupations  during the past five years.  As a group,  the Funds'  Trustees  and
officers own less than 1% of the  outstanding  shares of each Fund. Each Trustee
also serves as a Director of The Vanguard Group,  Inc., and as a Trustee of each
of the 103 funds administered by Vanguard (102 in the case of Mr. Malkiel and 93
in the case of Mr.  MacLaury).  The mailing address of the Trustees and officers
of the Funds is Post Office Box 876, Valley Forge, PA 19482.


                                      B-8
<PAGE>



JOHN J.  BRENNAN,  (DOB:  7/29/1954)  Chairman,  Chief  Executive  Officer,  and
Trustee*  Chairman,  Chief Executive Officer and Director of The Vanguard Group,
Inc., and Trustee of each of the investment companies in The Vanguard Group.

JOANN  HEFFERNAN  HEISEN,  (DOB:   1/25/1950)  Trustee  Vice  President,   Chief
Information  Officer,  and member of the  Executive  Committee  of  Johnson  and
Johnson  (Pharmaceuticals/Consumer  Products),  Director  of  Johnson  & Johnson
Consumer  Pharmaceuticals  Co.,  The Medical  Center at  Princeton,  and Women's
Research and Education Institute.

BRUCE K. MACLAURY,  (DOB:  5/7/1931) Trustee President Emeritus of The Brookings
Institution  (Independent  Non-Partisan  Research  Organization);   Director  of
American  Express  Bank,  Ltd.,  The St. Paul  Companies,  Inc.  (Insurance  and
Financial Services), and National Steel Corp.

BURTON G. MALKIEL,  (DOB:  8/28/1932) Trustee Chemical Bank Chairman's Professor
of Economics,  Princeton  University;  Director of  Prudential  Insurance Co. of
America, Banco Bilbao Gestinova,  Baker Fentress & Co. (Investment  Management),
The Jeffrey Co. (Holding Company), and Select Sector SPDR Trust (Exchange-Traded
Mutual Fund).

ALFRED M. RANKIN,  JR., (DOB:  10/8/1941)  Trustee  Chairman,  President,  Chief
Executive  Officer,  and  Director of NACCO  Industries,  Inc.  (Machinery/Coal/
Appliances);     and    Director    of    The    BFGoodrich    Co.     (Aircraft
Systems/Manufacturing/Chemicals).

JOHN C. SAWHILL,  (DOB: 6/12/1936) Trustee President and Chief Executive Officer
of The Nature Conservancy  (Non-Profit  Conservation Group); Director of Pacific
Gas   and   Electric   Co.,    Procter   &   Gamble   Co.,   NACCO    Industries
(Machinery/Coal/Appliances),  and Newfield  Exploration Co.  (Energy);  formerly
Director  and  Senior  Partner  of  McKinsey & Co.,  and  President  of New York
University.

JAMES O.  WELCH,  JR.,  (DOB:  5/13/1931)  Trustee  Retired  Chairman of Nabisco
Brands, Inc. (Food Products);  retired Vice Chairman and Director of RJR Nabisco
(Food and Tobacco Products); Director of TECO Energy, Inc., and Kmart Corp.

J. LAWRENCE WILSON,  (DOB: 3/2/1936) Trustee Retired Chairman of Rohm & Haas Co.
(Chemicals);  Director of Cummins Engine Co. (Diesel Engine  Company),  The Mead
Corp. (Paper Products),  and AmeriSource Health Corp.; and Trustee of Vanderbilt
University.

RAYMOND J.  KLAPINSKY,  (DOB:  12/7/1938)  Secretary*  Managing  Director of The
Vanguard Group,  Inc.;  Secretary of The Vanguard Group, Inc. and of each of the
investment companies in The Vanguard Group.

THOMAS J. HIGGINS,  (DOB: 5/21/1957) Treasurer* Principal of The Vanguard Group,
Inc.; Treasurer of each of the investment companies in The Vanguard Group.

ROBERT D. SNOWDEN,  (DOB: 9/4/1961) Controller* Principal of The Vanguard Group,
Inc.; Controller of each of the investment companies in The Vanguard Group.
- ---------

*Officers of the Funds are "interested persons" as defined in the 1940 Act.

THE VANGUARD GROUP

     Each Fund is a member of The Vanguard Group of Investment Companies,  which
consists of more than 100 funds.  Through their  jointly-owned  subsidiary,  The
Vanguard Group, Inc.  (Vanguard),  the Funds and the other funds in The Vanguard
Group   obtain   at  cost   virtually   all  of  their   corporate   management,
administrative,  and distribution  services.  Vanguard also provides  investment
advisory services on an at-cost basis to certain Vanguard funds.

     Vanguard  employs  a  supporting  staff of  management  and  administrative
personnel  needed  to  provide  the  requisite  services  to the  funds and also
furnishes the funds with  necessary  office space,  furnishings,  and equipment.
Each fund pays its share of Vanguard's  total expenses which are allocated among
the funds under  methods  approved  by the Board of  Trustees  of each fund.  In
addition,  each fund bears its own direct expenses such as legal,  auditing, and
custodian fees.


                                      B-9
<PAGE>


     The fund's officers are also officers and employees of Vanguard. No officer
or employee owns, or is permitted to own, any securities of any external adviser
for the funds.

     Vanguard  adheres to a Code of Ethics  established  pursuant  to Rule 17j-1
under the 1940 Act.  The Code is  designed  to  prevent  unlawful  practices  in
connection  with the purchase or sale of securities by persons  associated  with
Vanguard.  Under  Vanguard's  Code of Ethics  certain  officers and employees of
Vanguard who are  considered  access persons are permitted to engage in personal
securities  transactions.  However,  such transactions are subject to procedures
and  guidelines  similar  to,  and in many cases more  restrictive  than,  those
recommended by a blue ribbon panel of mutual fund industry executives.

     Vanguard was  established and operates under an Amended and Restated Funds'
Service  Agreement which was approved by the  shareholders of each of the funds.
The amounts  which each of the funds has invested are adjusted from time to time
in order to maintain the proportionate relationship between each fund's relative
net assets and its  contribution  to Vanguard's  capital.  At November 30, 1999,
each  Fund had  contributed  capital  to  Vanguard  (included  in other  assets)
representing  0.02% of each Fund's net assets.  The total amount  contributed by
the Funds was $10,547,000, which represented 10.6% of Vanguard's capitalization.
The Amended and Restated Funds' Service Agreement provides as follows:  (a) each
Vanguard fund may invest up to 0.40% of its current net assets in Vanguard,  and
(b) there is no other  limitation  on the dollar  amount that each Vanguard fund
may contribute to Vanguard's capitalization.

     MANAGEMENT.  Corporate management and administrative  services include: (1)
executive  staff;  (2) accounting and financial;  (3) legal and regulatory;  (4)
shareholder  account  maintenance;  (5)  monitoring  and  control  of  custodian
relationships;  (6)  shareholder  reporting;  and (7) review and  evaluation  of
advisory and other services provided to the funds by third parties.

     DISTRIBUTION.  Vanguard Marketing Corporation, a wholly-owned subsidiary of
The Vanguard Group, Inc., provides all distribution and marketing activities for
the funds in the Group. The principal distribution expenses are for advertising,
promotional  materials and marketing personnel.  Distribution  services may also
include  organizing  and offering to the public,  from time to time, one or more
new investment companies which will become members of Vanguard. The Trustees and
officers of Vanguard  determine the amount to be spent annually on  distribution
activities,  the  manner and  amount to be spent on each  fund,  and  whether to
organize new investment companies.

     One half of the distribution expenses of a marketing and promotional nature
is allocated  among the funds based upon relative net assets.  The remaining one
half of those expenses is allocated among the funds based upon each fund's sales
for the preceding 24 months relative to the total sales of the funds as a Group;
provided,  however,  that no fund's aggregate quarterly rate of contribution for
distribution expenses of a marketing and promotional nature shall exceed 125% of
average distribution expense rate for The Vanguard Group, and that no fund shall
incur  annual  distribution  expenses  in excess of 20/100 of 1% of its  average
month-end net assets.

     During the fiscal years ended November 30, 1997,  1998, and 1999, the Funds
incurred the following  approximate amounts of Vanguard's  management (including
transfer agency), distribution, and marketing expenses:

      FUND                               1997         1998           1999
      ----                               ----         ----           ----
      Prime Money Market Fund     $73,028,000  $92,226,000   $117,556,000
      Federal Money Market Fund     9,567,000   11,651,000     14,996,000
      Treasury Money Market Fund    9,310,000   11,151,000     13,619,000

     INVESTMENT ADVISORY SERVICES.  Vanguard also provides the Funds and several
other  Vanguard  funds with  investment  advisory  services.  These services are
provided on an at-cost basis from a money management staff employed  directly by
Vanguard.  The  compensation  and other  expenses  of this staff are paid by the
funds utilizing these services.

     During the fiscal years ended November 30, 1997,  1998, and 1999, the Funds
incurred the  following  approximate  amounts of The Vanguard  Group's  expenses
relating to investment advisory services.


                                      B-10
<PAGE>


      FUND                              1997        1998           1999
      ----                              ----        ----           ----
      Prime Money Market Fund     $3,782,000  $3,811,000     $4,718,000
      Federal Money Market Fund      489,000     475,000        584,000
      Treasury Money Market Fund     466,000     453,000        535,000

TRUSTEE COMPENSATION

     The same  individuals  serve as  Trustees of all  Vanguard  funds (with two
exceptions,  which are noted in the  table on page  B-14),  and each fund pays a
proportionate  share of the  Trustees'  compensation.  The  funds  employ  their
officers on a shared basis,  as well.  However,  officers are compensated by The
Vanguard Group, Inc., not the funds.

     INDEPENDENT TRUSTEES. The funds compensate their independent Trustees--that
is, the ones who are not also officers of the funds--in three ways:

- -    The  independent  Trustees  receive an annual fee for their  service to the
     funds, which is subject to reduction based on absences from scheduled Board
     meetings.

- -    The  independent  Trustees are reimbursed for the travel and other expenses
     that they incur in attending Board meetings.

- -    Upon retirement,  the independent  Trustees receive an aggregate annual fee
     of  $1,000  for each year  served  on the  Board,  up to  fifteen  years of
     service.  This annual fee is paid for ten years  following  retirement,  or
     until each Trustee's death.

     "INTERESTED"  TRUSTEES. Mr. Brennan serves as a Trustee, but is not paid in
this  capacity.  He is,  however,  paid in his role as officer  of The  Vanguard
Group, Inc.

     COMPENSATION TABLE. The following table provides  compensation  details for
each of the Trustees.  We list the amounts paid as  compensation  and accrued as
retirement benefits by the Funds for each Trustee. In addition,  the table shows
the total  amount of benefits  that we expect each  Trustee to receive  from all
Vanguard funds upon  retirement,  and the total amount of  compensation  paid to
each Trustee by all Vanguard funds.

                                        VANGUARD MONEY MARKET FUNDS
                                             COMPENSATION TABLE


<TABLE>
<CAPTION>
<S>                     <C>             <C>                  <C>                <C>
                                           PENSION OR                                 TOTAL
                         AGGREGATE         RETIREMENT                             COMPENSATION
                        COMPENSATION    BENEFITS ACCRUED     ESTIMATED ANNUAL   FROM ALL VANGUARD
                         FROM THESE     AS PART OF THESE      BENEFITS UPON       FUNDS PAID TO
 NAMES OF TRUSTEES        FUNDS(1)      FUNDS' EXPENSES(1)      RETIREMENT         TRUSTEES(2)

John C. Bogle(3)           None               None                  None               None
John J. Brennan            None               None                  None               None
Barbara Barnes
 Hauptfuhrer(3)            $748                $95               $15,000                 $0
JoAnn Heffernan Heisen   $8,978               $494               $15,000            $80,000
Bruce K. MacLaury        $9,299               $840               $12,000            $75,000
Burton G. Malkiel        $9,043               $819               $15,000            $80,000
Alfred M. Rankin, Jr.    $8,978               $599               $15,000            $80,000
John C. Sawhill          $8,978               $759               $15,000            $80,000
James O. Welch, Jr.      $8,978               $875               $15,000            $80,000
J. Lawrence Wilson       $8,978               $632               $15,000            $80,000
</TABLE>
- ---------
(1)  The amounts  shown in this column are based on the Funds' fiscal year ended
     November 30, 1999.
(2)  The amounts reported in this column reflect the total  compensation paid to
     each Trustee for his or her service as Trustee of 103  Vanguard  funds (102
     in the case of Mr.  Malkiel;  93 in the case of Mr.  MacLaury) for the 1999
     calendar year.
(3)  Mrs.  Hauptfuhrer  and Mr.  Bogle  have  retired  from  the  Funds'  Board,
     effective December 31, 1998 and December 31, 1999, respectively.


                                      B-11
<PAGE>


                              FINANCIAL STATEMENTS

     Each Fund's financial  statements as of and for the year ended November 30,
1999,  including the financial  highlights  for each of the five fiscal years in
the period ended  November 30, 1999,  appearing in the Funds' 1999 Annual Report
to  Shareholders,   and  the  report  thereon  of  PricewaterhouseCoopers   LLP,
independent  accountants,  also appearing therein, are incorporated by reference
in this Statement of Additional  Information.  For a more complete discussion of
the performance, please see the Funds' Annual Report to Shareholders,  which may
be obtained without charge.

                      DESCRIPTION OF SECURITIES AND RATINGS

A-1 AND PRIME-1 COMMERCIAL PAPER RATINGS

     Commercial  paper  rated  A-1  by  Standard  &  Poor's  has  the  following
characteristics:  (1) liquidity  ratios are adequate to meet cash  requirements;
(2) long-term  senior debt is rated "A" or better;  (3) the issuer has access to
at least two additional channels of borrowing;  (4) basic earnings and cash flow
have an  upward  trend  with  allowance  made  for  unusual  circumstances;  (5)
typically, the issuer's industry is well established and the issuer has a strong
position within the industry;  and (6) the reliability and quality of management
are  unquestioned.  Relative strength or weakness of the above factors determine
whether the issuer's commercial paper is A-1, A-2, or A-3. The rating Prime-1 is
the highest  commercial  paper  rating  assigned  by Moody's.  Among the factors
considered by Moody's in assigning ratings are the following:  (1) evaluation of
the management of the issuer;  (2) economic  evaluation of the issuer's industry
or industries and the appraisal of speculative-type  risks which may be inherent
in certain  areas;  (3)  evaluation  of the  issuer's  products  in  relation to
competition and customer  acceptance;  (4) liquidity;  (5) amount and quality of
long-term debt; (6) trend of earnings over a period of ten years;  (7) financial
strength of a parent company and the relationships  which exist with the issuer;
and (8) recognition by the management of obligations which may be present or may
arise as a result of public  interest  questions and  preparations  to meet such
obligations.

BOND RATINGS

     Bonds  rated AA by  Standard & Poor's  are  judged by S&P to be  high-grade
obligations,  and in the majority of instances differ only in small degrees from
issues  rated AAA (the AA rating may be  modified  by the  addition of a plus or
minus sign to show relative standing with the AA category).  Bonds rated AAA are
considered by S&P to be the highest grade  obligations  and possess the ultimate
degree of protection as to principal and interest. Bonds rated Aa by Moody's are
judged by Moody's to be of high quality by all standards.  Together with the Aaa
group,  they  comprise what are generally  known as high-grade  bonds.  They are
rated lower than Aaa bonds because  margins of protection may not be as large or
fluctuations of protective  elements may be of greater amplitude or there may be
other elements  present which make the long-term risks appear  somewhat  larger.
Moody's  also  supplies  numerical  indicators,  1,  2 and 3 to  the  Aa  rating
category. The modifier 1 indicates that the security is in the higher end of its
rating category;  the modifier 2 indicates a mid-range ranking and 3 indicates a
ranking toward the lower end of the category.

VARIABLE AMOUNT MASTER DEMAND NOTES

     Variable amount master demand notes are demand  obligations that permit the
investment of fluctuating  amounts at varying market rates of interest  pursuant
to an arrangement  between the issuer and a commercial  bank acting as agent for
the payees of such notes, whereby both parties have the right to vary the amount
of the  outstanding  indebtedness on the notes.  Because  variable amount master
demand notes are direct lending arrangements between a lender and a borrower, it
is not generally contemplated that such instruments will be traded, and there is
no secondary  market for these notes,  although  they are  redeemable  (and thus
immediately  repayable by the borrower) at face value, plus accrued interest, at
any time.  In  connection  with a Fund's  investment  in variable  amount master
demand notes, Vanguard's investment management staff will monitor, on an ongoing
basis,  the earning power,  cash flow and other liquidity  ratios of the issuer,
and the borrower's ability to pay principal and interest on demand.

                                      B-12
<PAGE>

DESCRIPTION OF U.S. GOVERNMENT SECURITIES

     As used in the Funds'  prospectus,  the term "U.S.  Government  Securities"
refers to a variety of  securities  which are issued or guaranteed by the United
States  Treasury,  by various agencies of the United States  Government,  and by
various instrumentalities which have been established or sponsored by the United
States   Government.   The  term   also   refers  to   "repurchase   agreements"
collateralized by such securities.

     U.S.  Treasury  Securities are backed by the "full faith and credit" of the
United States.  Securities issued or guaranteed by Federal agencies and the U.S.
Government  sponsored  instrumentalities  may or may not be  backed  by the full
faith and credit of the United  States.  In the case of securities not backed by
the full  faith  and  credit  of the  United  States,  the  investor  must  look
principally  to the  agency  or  instrumentality  issuing  or  guaranteeing  the
obligation for ultimate repayment, and may not be able to assert a claim against
the United  States  itself in the event the agency or  instrumentality  does not
meet its commitment.

     Some of the U.S.  Government  agencies  that issue or guarantee  securities
include   the   Export-Import   Bank  of  the  United   States,   Farmers   Home
Administration,  Federal Housing Administration,  Maritime Administration, Small
Business Administration, and The Tennessee Valley Authority.

     An instrumentality of the U.S.  Government is a government agency organized
under Federal charter with government supervision.  Instrumentalities issuing or
guaranteeing  securities  include,  among others,  Federal Home Loan Banks,  the
Federal Land Banks,  Central Bank for Cooperatives,  Federal Intermediate Credit
Banks, and the Federal National Mortgage Association.

DESCRIPTION OF REPURCHASE AGREEMENTS

     Repurchase  agreements  are  transactions  by  which a person  purchases  a
security  and  simultaneously  commits to resell that  security to the seller (a
member bank of the Federal Reserve System or recognized securities dealer) at an
agreed upon price on an agreed upon date  within a number of days  (usually  not
more than  seven)  from the date of  purchase.  The resale  price  reflects  the
purchase price plus an agreed upon market rate of interest which is unrelated to
the coupon rate or maturity of the purchased  security.  A repurchase  agreement
involves  the  obligation  of the seller to pay the  agreed  upon  price,  which
obligation is in effect secured by the value of the underlying security.

     The use of repurchase  agreements  involves certain risks. For example,  if
the  seller of the  agreement  defaults  on its  obligation  to  repurchase  the
underlying securities at a time when the value of these securities has declined,
the  Fund may  incur a loss  upon  disposition  of them.  If the  seller  of the
agreement becomes  insolvent and subject to liquidation or reorganization  under
the  Bankruptcy  Code or other laws, a bankruptcy  court may determine  that the
underlying  securities  are  collateral  not within the  control of the Fund and
therefore subject to sale by the trustee in bankruptcy.  Finally, it is possible
that the Fund may not be able to  substantiate  its  interest in the  underlying
securities. While the Funds' management acknowledges these risks, it is expected
that they can be controlled  through stringent  security  selection criteria and
careful monitoring procedures.

EURODOLLAR AND YANKEE OBLIGATIONS

     Eurodollar bank obligations are dollar-denominated  certificates of deposit
and time deposits issued outside the U.S. capital markets by foreign branches of
banks and by foreign  banks.  Yankee  bank  obligations  are  dollar-denominated
obligations issued in the U.S. capital markets by foreign banks.

     Eurodollar  and  Yankee  obligations  are  subject  to the same  risks that
pertain to domestic issues, notably credit risk, market risk and liquidity risk.
Additionally,  Eurodollar  (and to a limited  extent,  Yankee)  obligations  are
subject to certain  sovereign  risks.  One such risk is the  possibility  that a
sovereign  country might prevent capital,  in the form of dollars,  from flowing
across  their  borders.  Other risks  include:  adverse  political  and economic
developments;  the extent and  quality of  government  regulation  of  financial
markets and  institutions;  the  imposition of foreign  withholding  taxes;  and
expropriation or  nationalization  of foreign issuers.  However,  Eurodollar and
Yankee  obligations  will undergo the same credit analysis as domestic issues in
which the  Prime  Money  Market  Fund  invests,  and will have at least the same
financial  strength as the domestic  issuers approved for the Prime Money Market
Fund.

                                      B-13
<PAGE>


                              COMPARATIVE INDEXES

     Each of the investment  company  members of The Vanguard  Group,  including
Vanguard  Money  Market  Funds,  may  from  time to time  use one or more of the
following unmanaged indexes for comparative performance purposes.

STANDARD AND POOR'S 500 COMPOSITE STOCK PRICE INDEX--includes stocks selected by
Standard & Poor's  Index  Committee  to  include  leading  companies  in leading
industries and to reflect the U.S. stock market.

STANDARD & POOR'S  MIDCAP 400  INDEX--is  composed of 400 medium sized  domestic
stocks.

STANDARD & POOR'S  SMALLCAP  600/BARRA VALUE  INDEX--contains  stocks of the S&P
SmallCap 600 Index which have a lower than average price-to-book ratio.

STANDARD & POOR'S SMALLCAP  600/BARRA GROWTH  INDEX--contains  stocks of the S&P
SmallCap 600 Index which have a higher than average price-to-book ratio.

WILSHIRE  5000  EQUITY   INDEX--consists   of  more  than  7,000  common  equity
securities,  covering  all  stocks  in the  U.S.  for  which  daily  pricing  is
available.

WILSHIRE 4500 EQUITY  INDEX--consists  of all stocks in the Wilshire 5000 except
for the 500 stocks in the Standard and Poor's 500 Index.

RUSSELL  1000  VALUE  INDEX--consists  of the stocks in the  Russell  1000 Index
(comprising  the 1000  largest  U.S.-based  companies  measured by total  market
capitalization)  with the lowest  price-to-book  ratios,  comprising  50% of the
market capitalization of the Russell 1000.

RUSSELL 3000 STOCK INDEX--a diversified  portfolio of approximately 3,000 common
stocks  accounting for over 90% of the market value of publicly traded stocks in
the U.S.

RUSSELL 2000 STOCK INDEX--composed of the 2,000 smallest stocks contained in the
Russell  3000,  representing  approximately  7% of the Russell 3000 total market
capitalization.

RUSSELL 2000(R) VALUE INDEX--contains  stocks from the Russell 2000 Index with a
less-than-average growth orientation.

MORGAN  STANLEY  CAPITAL  INTERNATIONAL  EAFE  INDEX--is an  arithmetic,  market
value-weighted  average of the performance of over 900 securities  listed on the
stock exchanges of countries in Europe, Australia, Asia, and the Far East.

GOLDMAN SACHS 100  CONVERTIBLE  BOND  INDEX--currently  includes 71 bonds and 29
preferreds.   The  original  list  of  names  was  generated  by  screening  for
convertible  issues of $100  million or greater  in market  capitalization.  The
index is priced monthly.

SALOMON BROTHERS GNMA  INDEX--includes  pools of mortgages originated by private
lenders and guaranteed by the mortgage pools of the Government National Mortgage
Association.

SALOMON BROTHERS HIGH-GRADE  CORPORATE BOND  INDEX--consists of publicly issued,
non-convertible  corporate bonds rated Aa or Aaa. It is a value-weighted,  total
return index, including  approximately 800 issues with maturities of 12 years or
greater.

LEHMAN BROTHERS  LONG-TERM  TREASURY BOND INDEX--is a market weighted index that
contains  individually  priced U.S.  Treasury  securities  with maturities of 10
years or greater.

MERRILL LYNCH  CORPORATE & GOVERNMENT  BOND  INDEX--consists  of over 4,500 U.S.
Treasury, Agency and investment grade corporate bonds.

LEHMAN BROTHERS  CORPORATE (BAA) BOND INDEX--all  publicly  offered  fixed-rate,
nonconvertible  domestic  corporate bonds rated Baa by Moody's,  with a maturity
longer  than 1 year and with more  than $100  million  outstanding.  This  index
includes over 1,500 issues.

LEHMAN  BROTHERS  LONG-TERM  CORPORATE  BOND  INDEX--is  a subset of the  Lehman
Corporate  Bond Index  covering  all  corporate,  publicly  issued,  fixed-rate,
nonconvertible  U.S.  debt issues rated at least Baa, with at least $100 million
principal outstanding and maturity greater than 10 years.

BOND BUYER  MUNICIPAL BOND INDEX--is a yield index on current coupon  high-grade
general obligation municipal bonds.


                                      B-14
<PAGE>


STANDARD & POOR'S PREFERRED INDEX--is a yield index based upon the average yield
of four high-grade, non-callable preferred stock issues.

NASDAQ INDUSTRIAL INDEX--is composed of more than 3,000 industrial issues. It is
a  value-weighted  index  calculated  on price  change only and does not include
income.

COMPOSITE  INDEX--70%  Standard  & Poor's  500 Index and 30%  NASDAQ  Industrial
Index.

COMPOSITE  INDEX--65%  Standard  & Poor's  500  Index  and 35%  Lehman  Brothers
Long-Term Corporate AA or Better Bond Index.

COMPOSITE INDEX--65% Lehman Brothers Long-Term Corporate AA or Better Bond Index
and a 35% weighting in a blended  equity  composite (75% Standard & Poor's/BARRA
Value Index, 12.5% Standard & Poor's Utilities Index and 12.5% Standard & Poor's
Telephone Index).

LEHMAN BROTHERS  LONG-TERM  CORPORATE AA OR BETTER BOND  INDEX--consists  of all
publicly    issued,    fixed    rate,     nonconvertible    investment    grade,
dollar-denominated, SEC-registered corporate debt rated AA or AAA.

LEHMAN BROTHERS  AGGREGATE BOND INDEX--is a market-weighted  index that contains
individually priced U.S. Treasury,  agency, corporate, and mortgage pass-through
securities  corporate rated Baa- or better. The Index has a market value of over
$5 trillion.

LEHMAN  BROTHERS  MUTUAL  FUND  SHORT  (1-5)  GOVERNMENT/CORPORATE  INDEX--is  a
market-weighted index that contains  individually priced U.S. Treasury,  agency,
and  corporate  investment  grade  bonds  rated BBB- or better  with  maturities
between 1 and 5 years. The index has a market value of over $1.6 trillion.

LEHMAN BROTHERS MUTUAL FUND INTERMEDIATE (5-10) GOVERNMENT/CORPORATE INDEX--is a
market-weighted index that contains  individually priced U.S. Treasury,  agency,
and corporate  securities rated BBB- or better with maturities  between 5 and 10
years. The index has a market value of over $800 billion.

LEHMAN  BROTHERS  LONG (10+)  GOVERNMENT/CORPORATE  INDEX--is a  market-weighted
index that contains  individually  priced U.S.  Treasury,  agency, and corporate
securities rated BBB- or better with maturities greater than 10 years. The index
has a market value of over $1.1 trillion.

LIPPER SMALL  COMPANY  GROWTH FUND  AVERAGE--the  average  performance  of small
company  growth funds as defined by Lipper Inc.  Lipper  defines a small company
growth  fund as a fund that by  prospectus  or  portfolio  practice,  limits its
investments  to companies on the basis of the size of the company.  From time to
time,  Vanguard may advertise using the average  performance  and/or the average
expense ratio of the small company  growth funds.  (This fund category was first
established  in 1982.  For years prior to 1982,  the results of the Lipper Small
Company  Growth  category  were  estimated  using the  returns of the funds that
constituted the Group at its inception.)

LIPPER BALANCED FUND  AVERAGE--an  industry  benchmark of average balanced funds
with similar investment objectives and policies, as measured by Lipper Inc.

LIPPER  NON-GOVERNMENT  MONEY  MARKET FUND  AVERAGE--an  industry  benchmark  of
average non-government money market funds with similar investment objectives and
policies, as measured by Lipper Inc.

LIPPER  GOVERNMENT MONEY MARKET FUND AVERAGE--an  industry  benchmark of average
government money market funds with similar  investment  objectives and policies,
as measured by Lipper Inc.

LIPPER GENERAL EQUITY FUND  AVERAGE--an  industry  benchmark of average  general
equity funds with similar  investment  objectives  and policies,  as measured by
Lipper Inc.

LIPPER FIXED INCOME FUND AVERAGE--an  industry benchmark of average fixed income
funds with similar  investment  objectives  and policies,  as measured by Lipper
Inc.


                                      B-15
<PAGE>


                                                               SAI030-03/24/2000


<PAGE>


                                     PART C

                         VANGUARD MONEY MARKET RESERVES
                               OTHER INFORMATION


ITEM 23. EXHIBITS

(a)    Declaration of Trust**
(b)    By-Laws**
(c)    Reference is made to Articles III and V of the Registrant's Declaration
       of Trust
(d)    Investment Advisory Contract**
(e)    Not applicable
(f)    Reference is made to the section entitled "Management of the Funds" in
       the Registrant's Statement of Additional Information
(g)    Custodian Agreement*
(h)    Amended and Restated Funds' Service Agreement**
(i)    Legal Opinion**
(j)    Consent of Independent Accountants*
(k)    Not Applicable
(l)    Not Applicable
(m)    Not Applicable
(n)    Not Applicable
(o)    Not Applicable
- ------------------
  * Filed herewith
 ** Filed previously


ITEM 24. PERSONS CONTROLLED BY OR UNDER COMMON CONTROL WITH REGISTRANT

Registrant is not controlled by or under common control with any person.

ITEM 25. INDEMNIFICATION

The  Registrant's   organizational  documents  contain  provisions  indemnifying
Trustees and officers  against  liability  incurred in their official  capacity.
Article VII,  Section 2 of the Declaration of Trust provides that the Registrant
may  indemnify  and hold  harmless  each and every  Trustee and officer from and
against  any and all  claims,  demands,  costs,  losses,  expenses,  and damages
whatsoever  arising out of or related to the performance of his or her duties as
a Trustee or officer.  However,  this  provision does not cover any liability to
which a Trustee  or  officer  would  otherwise  be  subject by reason of willful
misfeasance,  bad faith,  gross negligence,  or reckless disregard of the duties
involved  in  the  conduct  of  his or her  office.  Article  VI of the  By-Laws
generally provides that the Registrant shall indemnify its Trustees and officers
from  any  liability  arising  out of  their  past or  present  service  in that
capacity.  Among other things,  this provision excludes any liability arising by
reason of willful  misfeasance,  bad faith,  gross  negligence,  or the reckless
disregard  of the duties  involved in the conduct of the  Trustee's or officer's
office with the Registrant.

ITEM 26. BUSINESS AND OTHER CONNECTIONS OF INVESTMENT ADVISER

The Vanguard Group, Inc.  (Vanguard) is an investment  adviser  registered under
the Advisers Act. The list required by this Item 26 of officers and directors of
Vanguard, together with any information as to any business profession, vocation,
or employment of a substantial  nature engaged in by such officers and directors
during the past two years, is incorporated  herein by reference from Schedules B
and D of Form ADV filed by Vanguard  pursuant to the  Advisers Act (SEC File No.
801-11953).


                                      C-1
<PAGE>

ITEM 27. PRINCIPAL UNDERWRITERS

(a)    Not Applicable
(b)    Not Applicable
(c)    Not Applicable

ITEM 28. LOCATION OF ACCOUNTS AND RECORDS

The books, accounts, and other documents required to be maintained by Section 31
(a) of the Investment  Company Act and the rules promulgated  thereunder will be
maintained  at the  offices of  Registrant;  Registrant's  Transfer  Agent,  The
Vanguard Group, Inc., 100 Vanguard Boulevard,  Malvern,  Pennsylvania 19355; and
the Registrant's Custodian, The Bank of New York, One Wall Street, New York, New
York 10286.

ITEM 29. MANAGEMENT SERVICES

Other than as set forth under the description of The Vanguard Group in Part B of
this   Registration   Statement,   the   Registrant   is  not  a  party  to  any
management-related service contract.

ITEM 30. UNDERTAKINGS

Not Applicable

                                      C-2

<PAGE>

                                   SIGNATURES

Pursuant to the  requirements  of the  Securities Act of 1933 and the Investment
Company  Act of 1940,  the  Registrant  hereby  certifies  that it meets all the
requirements for effectiveness of this Registration  Statement  pursuant to Rule
485(b) under the  Securities  Act of 1933 and has duly caused this  Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the Town of Valley Forge and the Commonwealth of Pennsylvania, on
the 8th day of March, 2000.


                                                VANGUARD MONEY MARKET RESERVES
                                            BY:_________________________________
                                                          (signature)
                                                         (HEIDI STAM)
                                                       JOHN J. BRENNAN*
                                            CHAIRMAN AND CHIEF EXECUTIVE OFFICER

     Pursuant  to  the   requirements  of  the  Securities  Act  of  1933,  this
Post-Effective  Amendment to the Registration Statement has been signed below by
the following persons in the capacities and on the date indicated:


          SIGNATURE                     TITLE                     DATE
- --------------------------------------------------------------------------------

By:/S/ JOHN J. BRENNAN        President, Chairman, Chief      March 8, 2000
   ---------------------------  Executive Officer, and Trustee
       (Heidi Stam)
      John J. Brennan*


By:/S/ JOANN HEFFERNAN HEISEN Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
     JoAnn Heffernan Heisen*


By:/S/ BRUCE K. MACLAURY      Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
      Bruce K. MacLaury*


By:/S/ BURTON G. MALKIEL      Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
       Burton G. Malkiel*


By:/S/ ALFRED M. RANKIN, JR.  Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
     Alfred M. Rankin, Jr.*


By:/S/ JOHN C. SAWHILL        Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
      John C. Sawhill*


By:/S/ JAMES O. WELCH, JR.    Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
     James O. Welch, Jr.*


By:/S/ J. LAWRENCE WILSON     Trustee                         March 8, 2000
   ---------------------------
       (Heidi Stam)
     J. Lawrence Wilson*


By:/S/ THOMAS J. HIGGINS      Treasurer, Principal Financial  March 8, 2000
   ---------------------------  Officer and Principal
       (Heidi Stam)             Accounting Officer
      Thomas J. Higgins*


*By Power of  Attorney.  See File Number  33-4424,  filed on January  25,  1999.
 Incorporated by Reference.

<PAGE>

                               INDEX TO EXHIBITS


Custodian Agreement ................................................... Ex-99.BG

Consent of Independent Accountants .................................... Ex-99.BJ






                                                                        EX-99.BG

                               CUSTODY AGREEMENT


     AGREEMENT,  dated as of October 22, 1999 between each  open-end  management
investment  company  listed on  Appendix A hereto as  amended  from time to time
(each such investment  company,  a "Fund") organized and existing under the laws
of the State of Delaware and  registered  with the U.S.  Securities and Exchange
Commission  under the  Investment  Company  Act of 1940,  as amended  (the "1940
Act"),  on behalf of certain of their series (each such series,  a "Series") and
The Bank of New York Company,  Inc., a New York  corporation  authorized to do a
banking  business  ("Custodian").  The  Funds'  principal  office  and  place of
business is P.O. Box 2600,  Valley Forge, PA 19482.  The  Custodian's  principal
office and place of business is One Wall Street, New York, New York 10286.


                                  WITNESSETH:

that for and in consideration of the mutual premises hereinafter set forth, each
Fund and Custodian agree as follows:


                                   ARTICLE I
                                  DEFINITIONS


     Whenever  used in this  Agreement,  the  following  words  shall  have  the
meanings set forth below:

     1.  "AUTHORIZED  PERSON"  shall be any person duly  authorized  by a Fund's
Board of Trustees to execute any Certificate or to give Oral  Instructions  with
respect to one or more Accounts,  such persons to be designated in a Certificate
annexed  hereto as  Appendix B or such other  Certificate  as may be received by
Custodian from time to time.


     2.  "AUTOFAX"  shall mean an unsigned  hard copy  facsimile  generated by a
Fund's computer system and transmitted to Custodian.


     3. "BNY AFFILIATE" shall mean any office,  branch or subsidiary of The Bank
of New York Company, Inc.


     4. "BOOK-ENTRY SYSTEM" shall mean the Federal  Reserve/Treasury  book-entry
system for receiving and delivering securities, its successors and nominees.


     5. "BUSINESS DAY" shall mean any day on which Custodian,  Book-Entry System
and relevant Depositories are open for business.


     6. "CERTIFICATE" shall mean any notice, instruction, or other instrument in
writing,  authorized  or required by this  Agreement  to be given to  Custodian,
which is actually received by Custodian by letter or facsimile  transmission and
signed  on  behalf  of a Fund by an  Authorized  Person  of the Fund or a person
reasonably believed by Custodian to be an Authorized Person.


     7. "DEPOSITORY"  shall include the Book-Entry  System, the Depository Trust
Company,  the Participants Trust Company,  and any other securities  depository,
book-entry  system or  clearing  agency  (and their  respective  successors  and
nominees)  authorized to act as a securities  depository,  book-entry  system or
clearing agency pursuant to applicable law and identified to a Fund.


     8. "INSTRUCTIONS" shall mean communications and facsimiles transmitted by a
Fund  by  electronic  or   telecommunications   media,   including   S.W.I.F.T.,
computer-to-computer  interface, dedicated transmission lines, telex or Autofax,
none of which are manually signed by a representative of a Fund.


     9. "ORAL INSTRUCTIONS" shall mean verbal instructions received by Custodian
from an Authorized Person or from a person  reasonably  believed by Custodian to
be an Authorized Person.


     10. "SECURITIES" shall include,  without  limitation,  any common stock and
other equity  securities,  bonds,  debentures and other debt securities,  notes,
mortgages  or other  obligations,  and any  instruments  representing  rights to
receive, purchase, or subscribe for the same, or representing

<PAGE>

any other rights or interests  therein (whether  represented by a certificate or
held in a Depository or by a Subcustodian).


     11. "SERIES" shall mean such of the various portfolios,  if any, of a Fund,
as are listed on Appendix A hereto.


     12.  "SHARES" shall mean the shares of beneficial  interest of a Fund, each
of which is, in the case of a Fund  having  Series,  allocated  to a  particular
Series.


     13. "SUBCUSTODIAN" shall mean a "bank" as defined in Section 2(a)(5) of the
1940 Act,  which is identified to a Fund and which  Custodian is required to use
to hold Securities purchased by a Fund from time to time.


                                   ARTICLE II
                       APPOINTMENT OF CUSTODIAN; ACCOUNTS


     1. (a) The Fund hereby  appoints  Custodian as custodian of all  Securities
and cash at any time delivered to Custodian  during the term of this  Agreement,
and authorizes  Custodian to hold  Securities in registered  form in its name or
the name of its nominees.  Custodian  hereby accepts such appointment and agrees
to establish and maintain one or more securities  accounts and cash accounts for
each Series in which Custodian will hold Securities and cash as provided herein.
Custodian shall maintain books and records segregating the assets of each Series
from the  assets  of any  other  Series.  Such  accounts  (each,  an  "Account";
collectively, the "Accounts") shall be in the name of the Series.


     (b) Custodian may from time to time establish on its books and records such
sub-accounts  within  each  Account  as  a  Fund  may  reasonably  request  in a
Certificate or Instructions (each, a "Special Account") and Custodian shall find
reasonably  acceptable,  and shall  reflect  therein such assets as the Fund may
specify in a Certificate or Instructions.


     (c)  Custodian  may  from  time to time  establish  pursuant  to a  written
agreement  with and for the  benefit  of a broker,  dealer,  futures  commission
merchant or other third party  identified in a Certificate or Instructions  such
accounts  on such terms and  conditions  as a Fund may  reasonably  request  and
Custodian shall find reasonably acceptable, and shall hold in such accounts such
Securities and cash as the Fund may specify in a Certificate or Instructions.


     2. Except as otherwise provided by law, a cash account shall constitute one
single and indivisible current Account.


                                   ARTICLE III
                   REPRESENTATIONS, WARRANTIES AND COVENANTS


     1. Each Fund hereby  represents  and warrants,  which  representations  and
warranties  shall be continuing  and shall be deemed to be reaffirmed  upon each
delivery of a Certificate or each giving of Oral Instructions or Instructions by
such Fund, that


     (a) It is duly organized and existing under the laws of the jurisdiction of
its organization,  with full power to carry on its business as now conducted, to
enter into this Agreement and to perform its obligations hereunder;


     (b) This Agreement has been duly authorized, executed and delivered by such
Fund, approved by a resolution of its Board of Trustees, constitutes a valid and
legally  binding  obligation of such Fund,  enforceable  in accordance  with its
terms,  except  as may be  limited  by  bankruptcy,  insolvency  or  other  laws
affecting  generally the  enforceability  of  creditors'  rights or by equitable
principles  generally applied,  and no statute,  regulation or rule,  applicable
solely to a Fund and not to  Custodian,  nor any  order,  judgment  or  contract
binding on such Fund  prohibits  such Fund's  execution or  performance  of this
Agreement;


     (c) It is  conducting  its  business  in  substantial  compliance  with all
applicable laws and requirements,  both state and federal,  and has obtained all
regulatory  licenses,  approvals and consents necessary to carry on its business
as now  conducted;  there is no provision of its charter or by-laws,  nor of any
mortgage,  indenture,  credit  agreement  or  other  contract  binding  on it or
affecting its property which would prohibit its execution or performance of this
Agreement;

<PAGE>

     (d) It will not use the  services  provided by  Custodian  hereunder in any
manner that is, or will result in, a violation  of any law,  rule or  regulation
applicable solely to such Fund, and not to Custodian;


     (e) It is fully  informed  of the  protections  and risks  associated  with
various  methods  of  transmitting   Instructions  and  Oral   Instructions  and
delivering Certificates to Custodian,  understands that there may be more secure
methods  of  transmitting  Instructions  and Oral  Instructions  and  delivering
Certificates  than the methods  selected by Custodian,  agrees that the security
procedures (if any) to be utilized provide a commercially  reasonable  degree of
protection in light of its particular  needs and  circumstances,  and will cause
each person transmitting Instructions to treat applicable user and authorization
codes,  passwords and authentication keys with extreme care, and has established
internal control and safekeeping  procedures to restrict the availability of the
same to persons duly authorized to give Instructions;


     (f) It shall insure, and agrees it is solely its responsibility,  that only
persons(s)  duly authorized by such Fund transmit  Instructions  and agrees that
Custodian may presume that an Instruction  including an Account number of a Fund
has been given by person(s) duly  authorized to transmit  Instructions  and need
not review any Instruction other than an Autofax;


     (g) It shall manage its  borrowings,  including,  without  limitation,  any
advance or overdraft  (including  any day-light  overdraft) in the Accounts,  so
that the aggregate of its total  borrowings  for each Series does not exceed the
amount such Series is permitted to borrow under the 1940 Act;


     (h) Its  transmission or giving of Instructions  pursuant to this Agreement
shall at all times comply with the 1940 Act;


     (i) It shall only instruct Custodian, whether by a Certificate, Instruction
or Oral Instruction,  to disburse cash (i) as hereinafter provided, (ii) for the
payment of dividends or distributions on, or redemptions of, Shares or (iii) for
other proper purposes;


     (j) It shall impose and maintain  limitations on the  destinations to which
cash may be disbursed by  Instructions  to ensure that each  disbursement  is in
accordance with the immediately preceding representation and warranty; and


     (k) It has the right to make the pledge and grant the security interest and
security  entitlement  to  Custodian  contained  in  paragraph  1 of Article VII
hereof,  free of any right or prior claim of any other person or entity  (except
as  otherwise  provided  by law),  such  pledge  and  grants  shall have a first
priority subject to no setoffs, counterclaims, or other liens or grants prior to
or on a parity therewith (except as otherwise provided by law).


     2. Custodian  hereby  represents and warrants,  which  representations  and
warranties  shall be continuing  and shall be deemed to be reaffirmed  upon each
receipt of a Certificate or each receipt of Oral Instructions or Instructions by
the Custodian, that:


     (a) It is duly organized and existing under the laws of the jurisdiction of
its organization,  with full power to carry on its business as now conducted, to
enter into this Agreement and to perform its obligations hereunder;


     (b) This  Agreement  has been duly  authorized,  executed and  delivered by
Custodian,  constitutes  a valid and legally  binding  obligation  of Custodian,
enforceable  in  accordance  with  its  terms,  except  as  may  be  limited  by
bankruptcy,  insolvency or other laws affecting  generally the enforceability of
creditors' rights or by equitable  principles generally applied, and no statute,
regulation or rule, applicable solely to Custodian, and not to any Fund, nor any
order, judgment or contract binding on Custodian prohibits Custodian's execution
or performance of this Agreement;


     (c) Custodian is conducting its business in substantial compliance with all
applicable laws and requirements,  both state and federal,  and has obtained all
regulatory  licenses,  approvals and consents necessary to carry on its business
as now  conducted;  there is no provision of its charter or by-laws,  nor of any
mortgage,  indenture,  credit  agreement  or  other  contract  binding  on it or
affecting its property which would prohibit its execution or performance of this
Agreement;


     (d) Custodian will not provide services hereunder in any manner that is, or
will result in, a violation of any law, rule or regulation  applicable solely to
Custodian, and not to the Funds;

<PAGE>

     (e)  Custodian  will  submit to the Funds on an annual  basis a copy of its
report  prepared in compliance  with the  requirements  of Statement of Auditing
Standards  No.  70  issued  by  the  American   Institute  of  Certified  Public
Accountants, as it may be amended from time to time; and


     (f) Custodian  shall maintain,  directly or through a third-party  selected
with reasonable care, adequate back-up computer and communication lines.


                                   ARTICLE IV
                          CUSTODY AND RELATED SERVICES


     1. (a) Subject to the terms hereof,  each Fund hereby authorizes  Custodian
to hold any Securities received by it from time to time for such Fund's account.
Custodian  shall be entitled to utilize  Depositories  to the extent possible in
connection  with its  performance  hereunder,  and  Subcustodians  as defined in
Article I of this  Agreement.  Securities and cash held in a Depository  will be
held subject to the rules,  terms and conditions of such entity.  Securities and
cash  held  through  Subcustodians  shall  be  held  subject  to the  terms  and
conditions of Custodian's agreements with such Subcustodians.  Subcustodians may
be authorized to hold  Securities in  Depositories  in which such  Subcustodians
participate.  Unless otherwise required by local law or practice or a particular
subcustodian agreement,  Securities deposited with Subcustodians will be held in
a  commingled  account  in the name of  Custodian  as  custodian  for the Funds.
Custodian  shall  identify  on its books and  records  the  Securities  and cash
belonging to each Fund and Series,  whether held directly or indirectly  through
Depositories or Subcustodians.


     (b) Unless  Custodian has received a  Certificate  or  Instructions  to the
contrary or  applicable  law or the rules of a particular  Depository  otherwise
require,  Custodian shall hold Securities indirectly through a Subcustodian or a
Depository  only if (i) the  Securities  are not  subject to any right,  charge,
security  interest,  lien or claim of any kind in favor of such  Subcustodian or
such  Depository  or the  creditors  or  operators  of any of them,  including a
receiver or trustee in  bankruptcy or similar  authority,  except for a claim of
payment  for the safe  custody  or  administration  of  Securities  or for funds
advanced  on  behalf  of a Fund by such  Subcustodian  or  Depository,  and (ii)
beneficial  ownership  of the  Securities  is freely  transferable  without  the
payment of cash or value other than for safe custody or administration.


     2. Promptly  after the close of business on each  Business  Day,  Custodian
shall furnish each Fund with confirmations and a summary, on a per Series basis,
of all  transfers  to or  from  the  Accounts,  either  hereunder  or  with  any
Subcustodian  appointed in accordance with this Agreement during said day. Where
Securities are  transferred to an Account for a Series,  Custodian shall also by
book-entry  or  otherwise  identify  as  belonging  to such Series a quantity of
Securities in a fungible bulk of Securities  registered in the name of Custodian
(or its nominee) or shown on Custodian's  account on the books of the Book-Entry
System or a Depository.  At least monthly and from time to time, Custodian shall
furnish  each Fund with a  detailed  statement,  on a per Series  basis,  of the
Securities and cash held by Custodian for such Fund.


     3. With respect to all Securities held hereunder,  Custodian shall,  unless
otherwise instructed to the contrary:


     (a) Collect and receive  all  income,  dividends,  distributions  and other
payments and promptly advise each Fund of any such amounts due but not paid;


     (b) Give  notice to each Fund and  present  payment  and collect the amount
payable  upon such  Securities  which  are  called,  but only if either  (i) the
Custodian  receives a written  notice of such call,  or (ii) notice of such call
appears in or is received from a nationally or  internationally  recognized bond
or corporate action service to which Custodian subscribes;


     (c) Unless  otherwise  instructed by a Fund,  Custodian shall retain in the
appropriate account any stock dividends,  subscription rights and other non-cash
distributions  on  the  Securities,  or  the  proceeds  from  the  sale  of  any
distributions.  Custodian  shall  notify a Fund upon the receipt of any non-cash
item;


     (d) Present for payment and collect the amount  payable upon all Securities
which mature,  promptly deposit or withdraw such proceeds as designated  therein
and advise each Fund as promptly as  practicable of any such amounts due but not
paid;


     (e) Surrender Securities in temporary form for definitive Securities;

<PAGE>

     (f) Promptly  forward to each Fund all notices,  proxies,  proxy soliciting
materials,   consents  and  other  written   information   (including,   without
limitation,  notices of tender  offers and exchange  offers,  pendency of calls,
maturities of Securities and expiration of rights)  relating to Securities  held
pursuant to this Agreement  which are actually  received by the  Custodian,  but
without indicating the manner in which such proxies or consents are to be voted;


     (g) Execute,  as custodian,  any  certificates  of  ownership,  affidavits,
declarations  or other  certificates  under  any tax laws  now or  hereafter  in
effect;


     (h) Hold  directly  or through the  Book-Entry  System or a  Depository  or
through a  Subcustodian  for the  account of a Series,  all  rights and  similar
Securities  issued  with  respect  to  any  Securities  credited  to an  Account
hereunder; and


     (i) Endorse for collection checks, drafts or other negotiable instruments.


     4. (a)  Whenever  Securities  (including,  but not  limited  to,  warrants,
options,  tenders,  options  to tender or  non-mandatory  puts or calls)  confer
optional  rights on a Fund or provide for  discretionary  action or  alternative
courses  of action by a Fund,  such Fund  shall be  responsible  for  making any
decisions  relating  thereto and for  directing  Custodian  to act. In order for
Custodian to act, it must receive such Fund's  Certificate  or  Instructions  at
Custodian's  offices,  addressed as Custodian may from time to time request, not
later than noon (New York time) at least two (2) Business Days prior to the last
scheduled  date to act with respect to such  Securities (or such earlier date or
time as Custodian may notify such Fund).  Absent  Custodian's  timely receipt of
such Certificate or  Instructions,  Custodian shall not be liable for failure to
take  any  action  relating  to or to  exercise  any  rights  conferred  by such
Securities,  unless Custodian has failed to act under  sub-paragraph (b) of this
paragraph  4 and such  failure  constitutes  negligence,  bad  faith or  willful
misconduct.


     (b)  Custodian  shall  notify  each Fund of such  rights  or  discretionary
actions or of the date or dates by when such  rights must be  exercised  or such
action must be taken  provided that  Custodian has actually  received,  from the
issuer or the relevant  Depository  (with  respect to  Securities  issued in the
United  States)  or  from  the  relevant  Subcustodian,  Depository  or  from  a
nationally or  internationally  recognized  bond or corporate  action service to
which  Custodian  subscribes,  timely  notice of such  rights  or  discretionary
corporate  action or of the date or dates such rights must be  exercised or such
action must be taken. Absent actual receipt of such notice, Custodian shall have
no liability for failing to so notify a Fund.


     5. Upon receipt of a Certificate and not otherwise, the Custodian, directly
or through the use of the Book-Entry System or a Depository shall:


     (a)  Execute  and  deliver  to  such  persons  as  may be  designated  in a
Certificate proxies, consents, authorizations, and any other instruments whereby
the  authority  of a Fund as  owner  of any  Securities  held  by the  Custodian
hereunder for the Series specified in the Certificate may be exercised;


     (b) Deliver any Securities  held by the Custodian  hereunder for the Series
specified in such Certificate in exchange for other Securities or cash issued or
paid in connection with the liquidation,  reorganization,  refinancing,  merger,
consolidation or  recapitalization  of any  corporation,  or the exercise of any
conversion  privilege and receive and hold hereunder  specifically  allocated to
such Series any cash or other Securities received in exchange;


     (c) Deliver any Securities  held by the Custodian  hereunder for the Series
specified  in  such  Certificate  to any  protective  committee,  reorganization
committee or other person in connection  with the  reorganization,  refinancing,
merger,  consolidation,  recapitalization  or sale of assets of any corporation,
and  receive  and hold  hereunder  specifically  allocated  to such  Series such
certificates of deposit,  interim receipts or other  instruments or documents as
may be issued to it to evidence such delivery;


     (d) Make such transfers or exchanges of the assets of the Series  specified
in such  Certificate,  and take  such  other  steps as shall be  stated  in such
Certificate to be for the purpose of  effectuating  any duly  authorized plan of
liquidation,  reorganization,  merger,  consolidation or  recapitalization  of a
Fund; and


     (e) Present for payment and collect the amount payable upon  Securities not
described  elsewhere in this  Agreement  which may be called as specified in the
Certificate.

<PAGE>


     6. All voting rights with respect to Securities,  however registered, shall
be  exercised by a Fund or its  designee.  For  Securities  issued in the United
States,  Custodian's  only  duty  shall be to mail to the  Funds  any  documents
(including  proxy  statements,  annual  reports  and  signed  proxies)  actually
received by  Custodian  relating to the  exercise  of such voting  rights.  With
respect to Securities issued outside of the United States, Custodian's only duty
shall be to provide  the  appropriate  Fund with  access to a provider of global
proxy services at such Fund's  request.  The Fund shall be  responsible  for all
costs associated with its use of such services.


     7. Custodian shall promptly advise a Fund upon  Custodian's  actual receipt
of  notification  of the partial  redemption,  partial  payment or other  action
affecting  less than all  Securities of the relevant  class.  If Custodian,  any
Subcustodian,  or any  Depository  holds any  Securities  in which a Fund has an
interest as part of a fungible mass, Custodian,  such Subcustodian or Depository
may select the  Securities to participate  in such partial  redemption,  partial
payment or other  action in any  non-discriminatory  manner that it  customarily
uses to make such selection.


     8.  Custodian  shall not under any  circumstances  accept  bearer  interest
coupons  which have been stripped  from United  States  federal,  state or local
government  or agency  securities  unless  explicitly  agreed to by Custodian in
writing.


     9. Each Fund shall be liable for all taxes,  assessments,  duties and other
governmental charges, including any interest or penalty thereto, with respect to
any cash or Securities  held on behalf of such Fund or any  transaction  related
thereto.


                                    ARTICLE V
                     SETTLEMENT OF SECURITIES TRANSACTIONS


     1. For the purpose of settling  Securities and  transactions,  a Fund shall
provide   Custodian  with  sufficient   immediately   available  funds  for  all
transactions by such time and date as conditions in the relevant market dictate.
As used herein,  "sufficient  immediately available funds" shall mean sufficient
cash.  Custodian shall provide each Fund with  immediately  available funds each
day which result from the actual settlement of all sale transactions, based upon
advices  received by Custodian from its  Subcustodians  and  Depositories.  Such
funds shall be in U.S. dollars.


                                   ARTICLE VI
                        PURCHASE AND SALE OF SECURITIES;
                               CREDITS TO ACCOUNT


     1. Promptly after each purchase or sale of Securities by a Fund,  such Fund
shall deliver to Custodian a Certificate or  Instructions,  or with respect to a
purchase or sale of a Security  generally required to be settled on the same day
the purchase or sale is made,  Oral  Instructions,  specifying  all  information
Custodian  may  reasonably  request to settle such  purchase or sale.  Custodian
shall account for all purchases and sales of Securities on the actual settlement
date unless otherwise agreed by Custodian.


     2. Each Fund  understands  that when  Custodian  is  instructed  to deliver
Securities  against payment,  delivery of such Securities and receipt of payment
therefor may not be completed  simultaneously.  Notwithstanding any provision in
this  Agreement  to  the  contrary,  settlements,  payments  and  deliveries  of
Securities may be effected by Custodian or any  Subcustodian  in accordance with
the  customary  or  established  securities  trading  or  securities  processing
practices and procedures in the  jurisdiction in which the  transaction  occurs,
including,  without limitations,  delivery to a purchaser or dealer therefor (or
agent) against  receipt with the expectation of receiving later payment for such
Securities.  Each Fund assumes  full  responsibility  for all risks,  including,
without limitation,  credit risks,  involved in connection with such delivery of
Securities  by  Custodian,  except the  foregoing  shall not excuse  Custodian's
acting in  accordance  with  such  practices  or  procedures  in a manner  which
constitutes negligence, bad faith or willful misconduct.


     3.  Custodian  may, as a matter of  bookkeeping  convenience or by separate
agreement  with a Fund,  credit the  Account  with the  proceeds  from the sale,
redemption or other  disposition  of Securities or interest,  dividends or other
distributions payable on Securities prior to its actual receipt of final payment
therefor. All such credits shall be conditional until Custodian's actual receipt
of final  payment  and may be  reversed  by  Custodian  to the extent that final
payment is not received. Custodian shall notify the appropriate Fund at least 48
hours prior to any such reversal,

<PAGE>

but such reversal shall be made as of the date  Custodian  determines it has not
received  final  payment.  Payment  with  respect to a  transaction  will not be
"final" until  Custodian shall have received  immediately  available funds which
under  applicable  local law,  rule and/or  practice  are  irreversible  and not
subject  to any  security  interest,  levy or other  encumbrance,  and which are
specifically applicable to such transaction.


                                   ARTICLE VII
                           OVERDRAFTS OR INDEBTEDNESS


     1. If Custodian  should in its sole  discretion  advance funds on behalf of
any Series which results in an overdraft  (including,  without any  limitations,
any  day-light  overdraft)  because the cash held by Custodian in an Account for
such Series  shall be  insufficient  to pay the total  amount  payable  upon the
purchase of Securities  specifically allocated to such Series, as set forth in a
Certificate, Instructions or Oral Instructions, or if an overdraft arises in the
separate  Account  of  a  Series  for  some  other  reason,  including,  without
limitation,  because of a reversal  of a  conditional  credit,  Custodian  shall
promptly notify the  appropriate  Fund of any such advance and the time at which
such advance or overdraft must be paid. Such advance,  overdraft or indebtedness
shall be  deemed  to be a loan made by  Custodian  to such Fund for such  Series
payable on demand and shall bear  interest  from the date incurred at a rate per
annum agreed by such Fund and Custodian from time to time, or, in the absence of
an agreement,  at the rate ordinarily  charged by Custodian to its institutional
customers.  In addition,  each Fund hereby agrees that Custodian  shall,  to the
maximum extent permitted by law, have a continuing lien,  security  interest and
security entitlement in and to such Securities of such Series as shall from time
to time have a fair market value equal to the aggregate amount of all overdrafts
of, and advances to, such Series,  together  with accrued  interest,  such lien,
security interest and security  entitlement to be effective only as long as such
advance,  overdraft, or accrued interest thereon remains outstanding.  Each Fund
authorizes Custodian to charge any such overdraft or indebtedness, together with
interest  due thereon,  against any balance of account  standing to such Series'
credit on Custodian's books.


                                  ARTICLE VIII
                         SALE AND REDEMPTION OF SHARES


     1.  Whenever a Fund shall sell any Shares,  it shall deliver to Custodian a
Certificate, Oral Instructions, or Instructions specifying the amount of cash to
be received by Custodian for the sale of such Shares and specifically  allocated
to an Account for such Series.


     2. Upon  receipt of such cash from such Fund's  transfer  agent,  Custodian
shall  credit  such cash to the Account in the name of the Series for which such
cash was received.


     3. Except as provided  hereinafter,  whenever a Fund  desires  Custodian to
make payment out of the cash held by Custodian  hereunder in  connection  with a
redemption  of any Shares,  it shall  furnish to Custodian a  Certificate,  Oral
Instructions,  or Instructions specifying the amount to be paid for such Shares,
and Custodian  shall make payment to the transfer  agent out of the cash held in
the Account of the Series the total amount specified in such  Certificate,  Oral
Instructions, or Instructions.


     4.  Notwithstanding  the above  provisions  regarding the redemption of any
Shares,  whenever  any  Shares are  redeemed  pursuant  to any check  redemption
privilege  which may from time to time be offered by a Fund,  Custodian,  unless
otherwise instructed by a Certificate, Oral Instructions or Instructions, shall,
upon request of such Fund's  transfer  agent,  charge the amount thereof against
the cash held in the Account of the Series of the Shares being redeemed.


                                   ARTICLE IX
                     PAYMENT OF DIVIDENDS OR DISTRIBUTIONS


     1. Each Fund shall furnish to Custodian a Certificate,  Oral  Instructions,
or Instructions  setting forth with respect to the Series specified  therein the
date of the declaration of a dividend or distribution,  the total amount payable
and the payable date.


     2. Upon the payment date specified in such  Certificate,  Oral Instructions
or  Instructions,  Custodian  shall pay out of the cash held for the  account of
each Series the total amount payable to

<PAGE>

the  dividend  agent  and any  sub-dividend  agent or  co-dividend  agent of the
appropriate Fund with respect to such Series specified therein.


                                    ARTICLE X
                              CONCERNING CUSTODIAN


     1. (a) Except as otherwise  expressly provided herein,  Custodian shall not
be liable for any costs,  expenses,  damages,  liabilities or claims,  including
attorneys'  and  accountants'  fees  (collectively,  "Losses"),  incurred  by or
asserted against a Fund, except those Losses arising out of the negligence,  bad
faith or willful misconduct of Custodian.


     (b) With  respect to any Losses  incurred by a Fund as a result of the acts
or the failure to act by any  Depository or any  Subcustodian  (other than a BNY
Affiliate),  Custodian shall take appropriate action to recover such Losses from
such Depository or such  Subcustodian;  and Custodian's sole  responsibility and
liability  to such Fund  shall be  limited  to  amounts  so  received  from such
Depository or such  Subcustodian  (exclusive  of costs and expenses  incurred by
Custodian),  except to the extent  that (A) any such  Subcustodian  is a parent,
subsidiary or otherwise affiliated with Custodian,  (B) Custodian's  negligence,
bad faith or willful  misconduct is the direct cause of such  Depository or such
Subcustodian's act or omission (it being agreed that Custodian's decision to use
any Subcustodian or any Depository shall not constitute  negligence,  bad faith,
or willful  misconduct),  or (C) a transaction or other matter between Custodian
and such Depository or such Subcustodian unrelated to the Funds was the cause of
the loss or damage, in each of which events,  Custodian shall be liable for such
Losses.


     (c) Custodian shall not be liable to a Fund or any third party for special,
indirect or consequential damages, or lost profits or loss of business,  arising
in connection with this Agreement,  nor shall BNY or any Subcustodian be liable:
(i) for acting in accordance  with any Certificate or Oral  Instructions  from a
Fund, or any Authorized Person of a Fund, or any Instructions; (ii) for the acts
or omissions of its  nominees,  correspondents,  agents (other than as specified
herein), any brokers or dealers, except to the extent that (A) any such nominee,
correspondent,  agent,  broker or dealer is a parent,  subsidiary  or  otherwise
affiliated with  Custodian,  (B)  Custodian's  negligence,  bad faith or willful
misconduct  is the direct  cause of such  nominee's,  correspondent's,  agent's,
broker's  or  dealer's  act or omission  or (C) a  transaction  or other  matter
between  Custodian  and such  nominee,  correspondent,  agent,  broker or dealer
unrelated  to the Funds was the  cause of the loss or  damage,  in each of which
events,  Custodian shall be liable; (iii) for holding property in any particular
country,  including,  but not limited to, Losses resulting from nationalization,
expropriation  or other  governmental  actions;  regulation  of the  banking  or
securities  industry;  availability  of cash or Securities or market  conditions
which prevent the transfer of property or execution of  Securities  transactions
or affect the value of property; or (iv) for any Losses due to forces beyond the
control of Custodian, including without limitation strikes, work stoppages, acts
of war or terrorism,  insurrection,  revolution, nuclear or natural catastrophes
or  acts  of  God,  or   interruptions,   loss  or  malfunctions  of  utilities,
communications or computer (hardware and software) services caused by any of the
foregoing, or the insolvency of any Subcustodian or of any Depository. Custodian
shall  endeavor  to  promptly  notify  the Funds  when it  becomes  aware of any
situation  outlined  above,  but shall not be liable for a failure to do so. The
Funds shall not be responsible for temporary  delays in the performance of their
duties and obligations hereunder and correspondingly shall not be liable for any
Losses  attributable to such delay in consequence of an event as described above
affecting the Funds' principal place of business  operations or  administration.
For the  avoidance of doubt,  Custodian  shall have no liability  for any Losses
arising  from the  applicability  of any law or  regulation  now or hereafter in
effect, or from the occurrence of any event, which may affect,  limit or prevent
the  transferability  or availability of any cash in the countries in which such
cash is held, except that the foregoing shall not excuse  Custodian's  acting or
not  acting  in  accordance  with  any  Certificate,   Oral   Instructions,   or
Instructions in a manner which  constitutes  negligence,  bad-faith,  or willful
misconduct.


     (d) Custodian may enter into  subcontracts,  agreements and  understandings
with any BNY  Affiliate,  whenever and on such terms and  conditions as it deems
necessary or appropriate to perform its services hereunder. No such subcontract,
agreement or  understanding  shall discharge  Custodian from its obligations and
liabilities hereunder.

<PAGE>

     (e) Each Fund agrees to  indemnify  Custodian  against  and hold  Custodian
harmless  from  any  and all  Losses  sustained  or  incurred  because  of or in
connection  with this  Agreement,  including  reasonable  fees and  expenses  of
counsel  incurred by Custodian  in a successful  defense of claims by such Fund;
provided, however, that the Funds shall not indemnify Custodian for those Losses
- --------  -------
arising out of Custodian's  negligence,  bad faith or willful  misconduct.  This
indemnity  shall  be a  continuing  obligation  of  each  Fund,  its  respective
successors and assigns, notwithstanding the termination of this Agreement.



     (f)  Custodian  agrees to  indemnify  each Fund  against and hold each Fund
harmless  from  any  and all  Losses  sustained  or  incurred  because  of or in
connection  with this  Agreement,  including  reasonable  fees and  expenses  of
counsel  incurred by the Funds in a successful  defense of claims by  Custodian,
provided,  however,  that  Custodian  shall only  indemnify  the Funds for those
- --------   -------
Losses arising out of Custodian's  negligence,  bad faith or willful misconduct,
and  provided  further,  that  Custodian  shall  not be  liable  to any Fund for
     --------  -------
special,  indirect or consequential  damages,  lost profits or loss of business.
This indemnity shall be a continuing obligation of Custodian, its successors and
assigns, notwithstanding the termination of this Agreement.


     2. Without  limiting the  generality of the foregoing,  Custodian  shall be
under no  obligation  to inquire  into,  and shall not be liable  (except to the
extent that either of (a) or (b) involves Custodian's  negligence,  bad faith or
willful misconduct) for:


     (a) Any Losses  incurred  by a Fund or any other  person as a result of the
receipt or acceptance of fraudulent, forged or invalid Securities, or Securities
which are otherwise not freely  transferable or deliverable  without encumbrance
in any relevant market;


     (b) The validity of the issue of any Securities purchased or sold by or for
a Fund;


     (c) The legality of the purchase, sale or writing of Securities by or for a
Fund, or the propriety of the amount paid or received therefor;


     (d) The legality of the sale or redemption of any Shares,  or the propriety
of the amount to be received or paid therefor;


     (e) The legality of the declaration or payment of any dividend by a Fund;


     (f) The legality of any borrowing by a Fund using Securities as collateral;


     (g) The legality of any loan of portfolio  Securities,  nor shall Custodian
be under any duty or obligation to see to it that any cash collateral  delivered
to it by a broker, dealer, or financial institution or held by it at any time as
a result of such loan of portfolio  Securities of a Fund is adequate  collateral
for such  Fund  against  any loss it might  sustain  as a result  of such  loan.
Custodian  specifically,  but not by way of  limitation,  shall not be under any
duty or  obligation  periodically  to check or notify a Fund that the  amount of
such cash collateral held by it for such Fund is sufficient  collateral for such
Fund, but such duty or obligation shall be the sole responsibility of such Fund.
In  addition,  Custodian  shall be under no duty or  obligation  to see that any
broker,  dealer or financial institution to which portfolio Securities of a Fund
are lent makes payment to it of any  dividends or interest  which are payable to
or for the  account  of such  Fund  during  the  period  of such  loan or at the
termination of such loan, provided, however that Custodian shall promptly notify
such Fund in the event that such dividends or interest are not paid and received
when due;


     (h) The sufficiency or value of any amounts of cash and/or  Securities held
in any Special  Account in connection with  transactions by a Fund;  whether any
broker,  dealer, futures commission merchant or clearing member makes payment to
a Fund of any variation margin payment or similar payment which such Fund may be
entitled to receive from such broker,  dealer,  futures  commission  merchant or
clearing  member,  or whether any payment received by Custodian from any broker,
dealer,  futures commission  merchant or clearing member is the amount a Fund is
entitled  to  receive,  or  to  notify  such  Fund  of  Custodian's  receipt  or
non-receipt of any such payment; or


     (i) Whether any  Securities  at any time  delivered to, or held by it or by
any  Subcustodian,  for the account of a Fund and  specifically  allocated  to a
Series are such as properly  may be held by such Fund or such  Series  under the
provisions  of  its  then  current   prospectus   and  statement  of  additional
information or (b) to ascertain  whether any transactions by a Fund,  whether or
not involving the Custodian, are such transactions as may properly be engaged in
by such Fund.

<PAGE>

     3. Custodian may, with respect to questions of law  specifically  regarding
an  Account,  obtain  the advice of counsel  and shall be fully  protected  with
respect to anything done or omitted by it in good faith in conformity  with such
advice.


     4.  Custodian  shall be under no  obligation  to take action to collect any
amount  payable on  Securities  in default,  or if payment is refused  after due
demand and  presentment,  unless and until (i) it shall be directed to take such
action by a  Certificate  or  Instructions  and (ii) it shall be  assured to its
satisfaction of reimbursement of its reasonable costs and expenses in connection
with any such action.


     5. Custodian  shall have no duty or  responsibility  to inquire into,  make
recommendations,  supervise,  or determine the  suitability of any  transactions
affecting any Account.


     6.  The  Funds  shall  pay to  Custodian  the fees  and  charges  as may be
specifically  agreed  upon from time to time and such other fees and  charges at
agreed rates for such services as may be applicable.


     7.  Custodian  has the  right to debit a cash  Account  (or any  subaccount
thereof)  as agreed  upon by  Custodian  and each Fund in advance for any amount
payable by a Fund in  connection  with any and all  obligations  of such Fund to
Custodian.


     8.  Custodian  shall  be  entitled  to rely  upon any  Certificate  or Oral
Instructions actually received by Custodian and reasonably believed by Custodian
to be duly authorized and delivered by an Authorized Person. Each Fund agrees to
forward to Custodian a Certificate or Instructions  confirming Oral Instructions
by the close of business of the same day that such Oral  Instructions  are given
to Custodian. Each Fund agrees that the fact that such confirming Certificate or
Instructions  are  not  received  or that a  contrary  Certificate  or  contrary
Instructions  are received by  Custodian  shall in no way affect the validity or
enforceability of transactions authorized by such Oral Instructions and effected
by Custodian  and under  either of the two  foregoing  circumstances,  Custodian
shall  promptly  notify the Funds.  If a Fund  elects to  transmit  Instructions
through an on-line  communications system offered by Custodian,  such Fund's use
thereof shall be subject to the Terms and Conditions attached hereto as Appendix
I.


     9. The books and records  pertaining  to a Fund which are in  possession of
Custodian  shall be the property of such Fund.  Such books and records  shall be
prepared and maintained as required by the 1940 Act and the rules thereunder and
other applicable  securities laws and rules and regulations.  Such Fund, or such
Fund's authorized  representatives,  shall have access to such books and records
during Custodian's normal business hours. Upon the reasonable request of a Fund,
copies of any such books and records shall be provided by Custodian to such Fund
or such Fund's  authorized  representative  free of charge.  Upon the reasonable
request of a Fund, Custodian shall provide in hard copy or on computer disc, any
records  included in any such  delivery  which are  maintained by Custodian on a
computer disc, or are similarly maintained.


     10. It is understood that Custodian is authorized to supply any information
regarding the Accounts  which is required by any law,  regulation or rule now or
hereafter  in effect.  The  Custodian  shall  provide  each Fund with any report
obtained  by the  Custodian  on the system of internal  accounting  control of a
Depository  or OCC,  and  with  such  reports  on its own  systems  of  internal
accounting control as the Fund may reasonably request from time to time.


     11.   Neither   Custodian   nor  any  Fund   shall   have  any   duties  or
responsibilities  whatsoever  except  such  duties and  responsibilities  as are
specifically set forth in this Agreement.


                                   ARTICLE XI
                                  TERMINATION


     Either party may  terminate  this  Agreement by giving to the other party a
notice in writing  specifying the date of such  termination,  which shall be not
less than  ninety  (90) days  after the date of such  notice.  In the event such
notice is given by a Fund, it shall be  accompanied  by a copy of the resolution
of the  Board of  Trustees  of such  Fund,  certified  by the  Secretary  or any
Assistant  Secretary,  electing to terminate  this  Agreement and  designating a
successor  custodian  or  custodians,  each of  which  shall  be a bank or trust
company having not less than $2,000,000 aggregate capital, surplus and undivided
profits.  In the event such notice is given by Custodian,  the Fund shall, on or
before the termination date, deliver to Custodian a copy of a resolution of the

<PAGE>

Boards of Trustees of the Fund,  certified  by the  Secretary  or any  Assistant
Secretary,  designating a successor  custodian or custodians.  In the absence of
such  designation by the Fund,  Custodian shall designate a successor  custodian
which shall be a bank or trust company having not less than $2,000,000 aggregate
capital,  surplus and undivided profits,  and which shall be satisfactory to the
Funds.  Upon the date set forth in such notice,  this Agreement  shall terminate
with respect to the affected Fund(s),  and the Custodian shall upon receipt of a
notice of acceptance by the successor custodian on that date deliver directly to
the successor  custodian all  Securities  and cash then owned by the Fund(s) and
held by it as  custodian,  after  deducting  all agreed upon fees,  expenses and
other  amounts  for the  payment  of  reimbursement  of which  it shall  then be
entitled.


     If a successor  custodian  is not  designated  by the Fund or  Custodian in
accordance with the preceding paragraph,  the Fund shall upon the date specified
in the  notice  of  termination  of this  Agreement  and  upon the  delivery  by
Custodian of all Securities  (other than Securities which cannot be delivered to
the Fund) and cash then owned by the Fund be deemed to be its own  custodian and
Custodian shall thereby be relieved of all duties and responsibilities  pursuant
to this Agreement,  other than the duty with respect to Securities  which cannot
be delivered to the Fund to hold such  Securities  hereunder in accordance  with
this Agreement.


                                   ARTICLE XII
                                  MISCELLANEOUS


     1. Each Fund agrees to furnish to Custodian a new Certificate of Authorized
Persons in the event of any change in the then present Authorized Persons. Until
such new  Certificate is received,  Custodian shall be fully protected in acting
upon Certificates or Oral Instructions of such present Authorized Persons.


     2. Any notice or other  instrument  in writing,  authorized  or required by
this  Agreement  to be  given  to  Custodian,  shall  be  sufficiently  given if
addressed to Custodian and received by it at its offices at One Wall Street, New
York, New York 10286,  or at such other place as Custodian may from time to time
designate in writing.


     3. Any notice or other  instrument  in writing,  authorized  or required by
this Agreement to be given to a Fund shall be sufficiently given if addressed to
the Fund and received by it at its offices at P.O. Box 2600,  Valley  Forge,  PA
19482,  Attn.:  Controller,  or at such other place as the Fund may from time to
time designate in writing.


     4. Each and every  right  granted to either  party  hereunder  or under any
other document delivered hereunder or in connection  herewith,  or allowed it by
law or equity,  shall be cumulative  and may be exercised  from time to time. No
failure on the part of any party to exercise,  and no delay in  exercising,  any
right will operate as a waiver thereof,  nor will any single or partial exercise
by either party of any right  preclude any other or future  exercise  thereof or
the exercise of any other right.


     5. In case any provision in or  obligation  under this  Agreement  shall be
invalid,  illegal or unenforceable in any jurisdiction,  the validity,  legality
and enforceability of the remaining  provisions shall not in any way be affected
thereby. This Agreement, other than the Appendix B hereto, may not be amended or
modified in any manner except by a written  agreement  executed by both parties.
This Agreement shall extend to and shall be binding upon the parties hereto, and
their respective successors and assigns; provided,  however, that this Agreement
                                         --------   -------
shall not be  assignable  by either  party  without the  written  consent of the
other.


     6. This  Agreement  shall be construed in accordance  with the  substantive
laws of the State of New York,  without  regard to conflicts of laws  principles
thereof. Each Fund and Custodian hereby consent to the jurisdiction of a federal
court situated in New York City, New York in connection with any dispute arising
hereunder.  Each Fund hereby irrevocably waives, to the fullest extent permitted
by  applicable  law, any  objection  which it may now or  hereafter  have to the
laying  of venue of any such  proceeding  brought  in such a court and any claim
that such proceeding brought in such a court has been brought in an inconvenient
forum. Each Fund and Custodian hereby each irrevocably waives any and all rights
to trial by jury in any legal  proceeding  arising  out of or  relating  to this
Agreement.


     7.  Notwithstanding  the fact that Custodian may from time to time maintain
an  Account  in the name of a third  party,  the  parties  hereto  agree that in
performing hereunder, Custodian is acting

<PAGE>

solely on behalf of the Funds and no contractual or service  relationship  shall
be deemed to be established hereby between Custodian and any such third party or
any other person.


     8. This  Agreement  is  executed on behalf of the Board of Trustees of each
Fund as Trustees and not  individually and the obligations of this Agreement are
not  binding  upon any of the  Trustees  or  shareholders  individually  but are
binding only upon the assets and property of such Funds;  further, the assets of
a particular  Series of such Fund shall under no  circumstances  be charged with
liabilities  attributable  to any other Series of such Fund and that all persons
extending  credit  to,  or  contracting  with or  having  any  claim  against  a
particular  Series of such Fund shall look only to the assets of that particular
Series for payment of such credit, contract or claim.


     9. The parties hereto agree that each shall treat  confidentially the terms
and conditions of this Agreement and all  information  provided by each party to
the other regarding its business and operations.  All  confidential  information
provided by a party hereto  shall be used by any other party  hereto  solely for
the purpose of rendering or obtaining  services  pursuant to this Agreement and,
except as may be required in carrying out this Agreement, shall not be disclosed
to any third  party  without  the prior  consent of such  providing  party.  The
foregoing shall not be applicable to any information that is publicly  available
when  provided or thereafter  becomes  publicly  available  other than through a
breach of this  Agreement,  or that is  required  to be  disclosed  by or to any
regulatory authority,  any external or internal accountant,  auditor or counsels
of the parties  hereto,  by judicial or  administration  process or otherwise by
applicable law, or to any disclosure made by a party if such party's counsel has
advised that such party could be liable under any applicable law or any judicial
or administrative order or process for a failure to make such disclosure.


     10. This Agreement may be executed in any number of  counterparts,  each of
which shall be deemed to be an original,  but such counterparts shall, together,
constitute only one instrument.

<PAGE>

     IN WITNESS  WHEREOF,  each Fund and Custodian have caused this Agreement to
be executed by their respective officers,  thereunto duly authorized,  as of the
day and year first above written.



                                   Each Fund Listed on Appendix A

                                   ________________________________

                                   By:_____________________________

                                   Title:__________________________



                                   THE BANK OF NEW YORK COMPANY, INC.

                                   By:______________________________

                                   Title:___________________________

<PAGE>

                                   APPENDIX I

                              THE BANK OF NEW YORK
                  ON-LINE COMMUNICATIONS SYSTEM (THE "SYSTEM")

                              TERMS AND CONDITIONS



     1. License;  Use. Upon delivery to the Funds of software enabling the Funds
        -------------
to obtain access to the System (the "Software"), Custodian grants to each Fund a
personal,  nontransferable  and nonexclusive  license to use the Software solely
for  the  purpose  of  transmitting  Instructions,   receiving  reports,  making
inquiries or otherwise  communicating  with  Custodian  in  connection  with the
Account(s).  Each Fund shall use the  Software  solely for its own  internal and
proper business purposes and not in the operation of a service bureau. Except as
set forth  herein,  no  license  or right of any kind is  granted to a Fund with
respect to the Software. Each Fund acknowledges that Custodian and its suppliers
retain  and  have  title  and  exclusive  proprietary  rights  to the  Software,
including any trade secrets or other ideas, concepts, know-how, methodologies or
information  incorporated  therein and the exclusive  rights to any  copyrights,
trademarks  and  patents   (including   registrations   and   applications   for
registration of either),  or other statutory or legal  protections  available in
respect  thereof.  Each  Fund  further  acknowledges  that  all or a part of the
Software may be  copyrighted or  trademarked  (or a  registration  or claim made
therefor)  by  Custodian  or its  suppliers.  No Fund shall take any action with
respect to the Software  inconsistent with the foregoing  acknowledgements,  nor
shall any Fund attempt to decompile, reverse engineer or modify the Software. No
Fund may copy,  sell,  lease or  provide,  directly  or  indirectly,  any of the
Software  or  any  portion  thereof  to  any  other  person  or  entity  without
Custodian's  prior written consent.  No Fund may remove any statutory  copyright
notice or other notice  included in the Software or on any media  containing the
Software.  Each Fund shall reproduce any such notice on any  reproduction of the
Software  and  shall  add  statutory  copyright  notice  or other  notice to the
Software  or  media  upon  Custodian's  request.  Custodian  agrees  to  provide
reasonable  training,  instruction manuals and access to Custodian's "help desk"
in connection with each Fund's user support necessary to use the Software.  At a
Fund's request, Custodian agrees to permit reasonable testing of the Software by
any Fund.


     2.  Proprietary  Information.  The  Software,  any data  base  (other  than
         ------------------------
databases  relating solely to the assets of a Fund and transactions with respect
thereto) and any proprietary data, processes, information and documentation made
available to the Fund (other than which are or become part of the public  domain
or are legally required to be made available to the public)  (collectively,  the
"Information"),  are the exclusive and confidential property of Custodian or its
suppliers.  The Fund shall keep the  Information  confidential by using the same
care and  discretion  that the Fund uses with  respect  to its own  confidential
property and trade secrets,  but not less than reasonable care. Upon termination
of the Agreement or the Software license granted herein for any reason, the Fund
shall return to Custodian any and all copies of the Information which are in its
possession or under its control.


     3.  Indemnification.  Custodian  will indemnify and hold harmless the Funds
         ---------------
with respect to any  liability,  damages,  loss or claim  incurred by or brought
against  any Fund by reason of any claim or  infringement  against  any  patent,
copyright,  license or other property right arising out or by reason of a Fund's
use of the Software in the form provided under this  Appendix.  Custodian at its
own  expense  will defend  such  action or claim  brought  against a Fund to the
extent  that it is based on a claim that the  Software  in the form  provided by
Custodian  infringes any patents,  copyrights,  license or other property right,
provided  that  Custodian  is  provided  with  reasonable  notice of such claim,
provided that the Fund has not settled,  compromised or confessed any such claim
without the Custodian's  written consent, in which event Custodian shall have no
liability or obligation hereunder, and provided Fund cooperates with and assists
Custodian  in the  defense  of such  claim.  Custodian  shall  have the right to
control the defense of all such claims, lawsuits and other proceedings. If, as a
result of any claim of infringement  against any patent,  copyright,  license or
other  property  right,  Custodian is enjoined  from using the  Software,  or if
Custodian believes that the System is likely to become the subject of a claim of
infringement,  Custodian  may in its sole  discretion  either (a) at its expense
procure the right for the Funds to continue to use the Software, or

<PAGE>

(b) replace or modify the Software so as to make it  non-infringing,  or (c) may
discontinue the license granted herein upon written notice to the Funds.


     4.  Modifications.  Custodian  reserves the right to modify the Software at
         -------------
its own expense  from time to time and a Fund shall  install new releases of the
Software as Custodian  may direct.  Each Fund agrees not to modify or attempt to
modify  the  Software  without  Custodian's  prior  written  consent.  Each Fund
acknowledges  that  any  modifications  to the  Software,  whether  by a Fund or
Custodian  and whether  with or without  Custodian's  consent,  shall become the
property of Custodian.


     5. NO  REPRESENTATIONS  OR WARRANTIES.  CUSTODIAN AND ITS MANUFACTURERS AND
        ----------------------------------
SUPPLIERS  MAKE NO WARRANTIES OR  REPRESENTATIONS  WITH RESPECT TO THE SOFTWARE,
SERVICES OR ANY DATABASE,  EXPRESS OR IMPLIED,  IN FACT OR IN LAW, INCLUDING BUT
NOT LIMITED TO  WARRANTIES  OF  MERCHANTABILITY  AND  FITNESS  FOR A  PARTICULAR
PURPOSE. EACH FUND ACKNOWLEDGES THAT THE SOFTWARE, SERVICES AND ANY DATABASE ARE
PROVIDED "AS IS." IN NO EVENT SHALL  CUSTODIAN OR ANY SUPPLIER BE LIABLE FOR ANY
DAMAGES,  WHETHER DIRECT, INDIRECT,  SPECIAL OR CONSEQUENTIAL,  WHICH A FUND MAY
INCUR IN  CONNECTION  WITH  THE  SOFTWARE,  SERVICES  OR ANY  DATABASE,  EVEN IF
CUSTODIAN OR SUCH SUPPLIER HAS BEEN ADVISED OF THE  POSSIBILITY OF SUCH DAMAGES.
IN NO EVENT SHALL  CUSTODIAN OR ANY SUPPLIER BE LIABLE FOR ACTS OF GOD,  MACHINE
OR  COMPUTER   BREAKDOWN  OR   MALFUNCTION,   INTERRUPTION   OR  MALFUNCTION  OF
COMMUNICATION FACILITIES,  LABOR DIFFICULTIES OR ANY OTHER SIMILAR OR DISSIMILAR
CAUSE BEYOND THEIR REASONABLE CONTROL.


     6. Security;  Reliance;  Unauthorized Use. Each Fund will cause all persons
        --------------------------------------
utilizing the Software and System to treat all applicable user and authorization
codes,  passwords and authentication keys with extreme care. Custodian is hereby
irrevocably  authorized  to act in  accordance  with  and  rely on  Instructions
received by it through the System.  Each Fund  acknowledges  that it is its sole
responsibility  to assure that only persons duly authorized by such Fund use the
System  and  that  Custodian   shall  not  be  responsible  or  liable  for  any
unauthorized use thereof.


     7. System Acknowledgements.  Custodian shall acknowledge through the System
        -----------------------
its receipt of each  transmission  communicated  through the System,  and in the
absence of such acknowledgement Custodian shall not be liable for any failure to
act in accordance  with such  transmission  and the Fund may not claim that such
transmission was received by Custodian.


     8. EXPORT  RESTRICTIONS.  EXPORT OF THE  SOFTWARE IS  PROHIBITED  BY UNITED
        --------------------
STATES LAW. THE FUNDS MAY NOT UNDER ANY CIRCUMSTANCES RESELL, DIVERT,  TRANSFER,
TRANSSHIP OR OTHERWISE  DISPOSE OF THE SOFTWARE (IN ANY FORM) IN OR TO ANY OTHER
COUNTRY.  IF CUSTODIAN  DELIVERED THE SOFTWARE TO THE FUND OUTSIDE OF THE UNITED
STATES,  THE SOFTWARE WAS EXPORTED FROM THE UNITED STATES IN ACCORDANCE WITH THE
EXPORTER  ADMINISTRATION   REGULATIONS.   DIVERSION  CONTRARY  TO  U.S.  LAW  IS
PROHIBITED. Each Fund hereby authorizes Custodian to report its name and address
to  government   agencies  to  which  Custodian  is  required  to  provide  such
information by law.


     9. ENCRYPTION. Each Fund acknowledges and agrees that encryption may not be
        ----------
available for every communication through the System, or for all data. Each Fund
agrees  that  Custodian  may  deactivate  any  encryption  features at any time,
without prior or  contemporaneous  notice,  or liability,  to such Fund, for the
purpose of repairing or  troubleshooting  the System or the Software.  Custodian
shall  promptly  advise  each  Fund  whenever   Custodian  has  deactivated  any
encryption  features.  Custodian also may  deactivate  any encryption  features,
without liability to a Fund, for the purpose of scheduled  maintenance,  so long
as it provides reasonable advance notice to the Fund.

<PAGE>

                                   APPENDIX A



FUND:                          Vanguard Admiral Funds

SERIES/TAX IDENTIFICATION NO.: Vanguard Admiral Treasury Money Market
                               Fund/23-2696041



FUND:                          Vanguard Money Market Reserves

SERIES/TAX IDENTIFICATION NO.: Vanguard Prime Money Market Fund/23-6607979

                               Vanguard Federal Money Market Fund/23-2439136



FUND:                          Vanguard Treasury Fund

SERIES/TAX IDENTIFICATION NO.: Vanguard Treasury Money Market Fund/23-2439140



FUND:                          Vanguard Variable Insurance Funds

SERIES/TAX IDENTIFICATION NO.: Money Market Portfolio/23-2585135




                                                                Exhibit EX-99.BJ



                       CONSENT OF INDEPENDENT ACCOUNTANTS

We hereby  consent to the  incorporation  by reference in the  Prospectuses  and
Statement of Additional  Information  constituting parts of this  Post-Effective
Amendment No. 58 to the registration  statement on Form N-1A (the  "Registration
Statement")  of our report  dated  January 6, 2000,  relating  to the  financial
statements  and financial  highlights  appearing in the November 30, 1999 Annual
Report  to  Shareholders  of  Vanguard  Money  Market  Reserves,  which are also
incorporated by reference into the  Registration  Statement.  We also consent to
the  references  to  us  under  the  heading   "Financial   Highlights"  in  the
Prospectuses  and  under  the  headings  "Financial   Statements"  and  "Service
Providers--Independent Accountants" in the Statement of Additional Information.


PricewaterhouseCoopers LLP
Philadelphia, PA

March 2, 2000





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