<PAGE> PAGE 1
000 A000000 05/31/1999
000 C000000 0000106830
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 U
001 A000000 VANGUARD MONEY MARKET RESERVES
001 B000000 811-2554
001 C000000 6106691000
002 A000000 100 VANGUARD BOULEVARD
002 B000000 MALVERN
002 C000000 PA
002 D010000 19355
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 2
007 C010100 1
007 C020100 VANGUARD PRIME MONEY MARKET FUND
007 C030100 N
007 C010200 2
007 C020200 VANGUARD FEDERAL MONEY MARKET FUND
007 C030200 N
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
010 A00AA01 THE VANGUARD GROUP, INC.
010 B00AA01 801-11953
010 C01AA01 MALVERN
010 C02AA01 PA
010 C03AA01 19355
012 A00AA01 THE VANGUARD GROUP, INC.
012 B00AA01 84-772
012 C01AA01 MALVERN
012 C02AA01 PA
012 C03AA01 19355
013 A00AA01 PRICEWATERHOUSECOOPERS LLP
013 B01AA01 PHILADELPHIA
013 B02AA01 PA
013 B03AA01 19103
014 A00AA01 VANGUARD MARKETING CORPORATION
<PAGE> PAGE 2
014 B00AA01 8-21570
015 A00AA01 FIRST UNION NATIONAL BANK
015 B00AA01 C
015 C01AA01 PHILADELPHIA
015 C02AA01 PA
015 C03AA01 19101
015 E01AA01 X
018 00AA00 Y
019 A00AA00 Y
019 B00AA00 102
019 C00AA00 VANGUARDGR
020 C000001 0
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 0
022 A000001 GOLDMAN SACHS & CO.
022 B000001 13-5108880
022 C000001 11440806
022 D000001 984985
022 A000002 NATIONSBANK-TEXAS
022 C000002 7005000
022 D000002 0
022 A000003 MERRILL LYNCH PIERCE FENNER & SMITH
022 B000003 13-5674085
022 C000003 8959648
022 D000003 171672
022 A000004 LEHMAN BROTHERS INC.
022 B000004 13-2518466
022 C000004 5164537
022 D000004 388589
022 A000005 J.P. MORGAN SECURITIES INC.
022 B000005 13-3224016
022 C000005 3984404
022 D000005 912186
022 A000006 CREDIT SUISSE FIRST BOSTON CORP.
022 B000006 13-5659485
022 C000006 2942279
022 D000006 794458
022 A000007 MORGAN STANLEY & CO, INCORPORATED
022 B000007 13-2655998
022 C000007 3502540
022 D000007 68183
022 A000008 SALOMON SMITH BARNEY
022 B000008 13-1912900
<PAGE> PAGE 3
022 C000008 2893739
022 D000008 462509
022 A000009 FORD MOTOR CO.
022 C000009 2684884
022 D000009 0
022 A000010 CHASE SECURITIES INC.
022 B000010 13-3112953
022 C000010 2667714
022 D000010 37433
023 C000000 80459588
023 D000000 5669381
026 A000000 N
026 B000000 N
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
029 00AA00 N
030 A00AA00 0
030 B00AA00 0.00
030 C00AA00 0.00
034 00AA00 N
035 00AA00 0
036 B00AA00 0
038 00AA00 0
039 00AA00 N
040 00AA00 N
048 00AA00 0.000
048 A01AA00 0
048 A02AA00 0.000
048 B01AA00 0
048 B02AA00 0.000
048 C01AA00 0
048 C02AA00 0.000
048 D01AA00 0
048 D02AA00 0.000
048 E01AA00 0
048 E02AA00 0.000
048 F01AA00 0
048 F02AA00 0.000
048 G01AA00 0
048 G02AA00 0.000
048 H01AA00 0
048 H02AA00 0.000
048 I01AA00 0
048 I02AA00 0.000
048 J01AA00 0
<PAGE> PAGE 4
048 J02AA00 0.000
048 K01AA00 0
048 K02AA00 0.000
055 A00AA00 N
055 B00AA00 N
056 00AA00 N
057 00AA00 N
058 A00AA00 N
059 00AA00 Y
060 A00AA00 Y
060 B00AA00 Y
061 00AA00 3000
066 A00AA00 N
067 00AA00 N
068 A00AA00 N
068 B00AA00 N
069 00AA00 N
077 A000000 Y
077 D000000 Y
080 C00AA00 0
081 B00AA00 0
082 A00AA00 N
082 B00AA00 0
083 A00AA00 N
083 B00AA00 0
084 A00AA00 N
084 B00AA00 0
085 A00AA00 Y
085 B00AA00 N
086 A010000 0
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
024 000100 N
025 A000101 DELETE
025 D000101 0
025 A000102 DELETE
025 D000102 0
025 D000103 0
025 D000104 0
025 D000105 0
025 D000106 0
025 D000107 0
<PAGE> PAGE 5
025 D000108 0
028 A010100 4391208
028 A020100 140828
028 A030100 0
028 A040100 4142620
028 B010100 5576111
028 B020100 142867
028 B030100 0
028 B040100 4811743
028 C010100 3986616
028 C020100 127685
028 C030100 0
028 C040100 3236528
028 D010100 5162735
028 D020100 144159
028 D030100 0
028 D040100 4088517
028 E010100 4945072
028 E020100 140043
028 E030100 0
028 E040100 5241195
028 F010100 3984489
028 F020100 144620
028 F030100 0
028 F040100 3789727
028 G010100 28046231
028 G020100 840202
028 G030100 0
028 G040100 25310330
028 H000100 0
042 A000100 0
042 B000100 0
042 C000100 0
042 D000100 0
042 E000100 0
042 F000100 0
042 G000100 0
042 H000100 0
043 000100 0
044 000100 0
062 A000100 Y
062 B000100 1.6
062 C000100 27.3
062 D000100 0.0
062 E000100 0.0
062 F000100 17.3
062 G000100 4.5
062 H000100 0.0
062 I000100 42.4
062 J000100 0.0
062 K000100 0.0
<PAGE> PAGE 6
062 L000100 6.6
062 M000100 0.0
062 N000100 0.0
062 O000100 0.0
062 P000100 0.0
062 Q000100 0.0
062 R000100 0.3
063 A000100 73
063 B000100 0.0
064 A000100 N
070 A010100 Y
070 A020100 N
070 B010100 N
070 B020100 N
070 C010100 N
070 C020100 N
070 D010100 N
070 D020100 N
070 E010100 N
070 E020100 N
070 F010100 N
070 F020100 N
070 G010100 N
070 G020100 N
070 H010100 N
070 H020100 N
070 I010100 N
070 I020100 N
070 J010100 Y
070 J020100 N
070 K010100 N
070 K020100 N
070 L010100 Y
070 L020100 Y
070 M010100 N
070 M020100 N
070 N010100 Y
070 N020100 N
070 O010100 Y
070 O020100 N
070 P010100 Y
070 P020100 N
070 Q010100 N
070 Q020100 N
070 R010100 N
070 R020100 N
071 A000100 0
071 B000100 0
071 C000100 0
071 D000100 0
072 A000100 6
<PAGE> PAGE 7
072 B000100 936514
072 C000100 0
072 D000100 0
072 E000100 0
072 F000100 2165
072 G000100 17565
072 H000100 0
072 I000100 34170
072 J000100 516
072 K000100 0
072 L000100 428
072 M000100 29
072 N000100 0
072 O000100 0
072 P000100 0
072 Q000100 0
072 R000100 15
072 S000100 0
072 T000100 4773
072 U000100 0
072 V000100 0
072 W000100 0
072 X000100 59661
072 Y000100 8
072 Z000100 876861
072AA000100 33
072BB000100 0
072CC010100 0
072CC020100 0
072DD010100 844084
072DD020100 32777
072EE000100 0
073 A010100 0.0240
073 A020100 0.0250
073 B000100 0.0000
073 C000100 0.0000
074 A000100 0
074 B000100 0
074 C000100 38334554
074 D000100 0
074 E000100 0
074 F000100 0
074 G000100 0
074 H000100 0
074 I000100 5643
074 J000100 0
074 K000100 0
074 L000100 359994
074 M000100 0
074 N000100 38700191
074 O000100 50046
<PAGE> PAGE 8
074 P000100 16015
074 Q000100 0
074 R010100 0
074 R020100 0
074 R030100 0
074 R040100 182667
074 S000100 0
074 T000100 38451463
074 U010100 37193641
074 U020100 1258309
074 V010100 1.00
074 V020100 1.00
074 W000100 0.9999
074 X000100 1289789
074 Y000100 0
075 A000100 36999689
075 B000100 0
076 000100 0.00
024 000200 N
028 A010200 532553
028 A020200 17075
028 A030200 0
028 A040200 344290
028 B010200 423291
028 B020200 17290
028 B030200 0
028 B040200 455560
028 C010200 346582
028 C020200 15719
028 C030200 0
028 C040200 281000
028 D010200 455347
028 D020200 17531
028 D030200 0
028 D040200 332508
028 E010200 393601
028 E020200 17058
028 E030200 0
028 E040200 392914
028 F010200 327012
028 F020200 17692
028 F030200 0
028 F040200 294129
028 G010200 2478386
028 G020200 102365
028 G030200 0
028 G040200 2100401
028 H000200 0
042 A000200 0
042 B000200 0
042 C000200 0
<PAGE> PAGE 9
042 D000200 0
042 E000200 0
042 F000200 0
042 G000200 0
042 H000200 0
043 000200 0
044 000200 0
062 A000200 Y
062 B000200 0.0
062 C000200 93.4
062 D000200 6.3
062 E000200 0.0
062 F000200 0.0
062 G000200 0.0
062 H000200 0.0
062 I000200 0.0
062 J000200 0.0
062 K000200 0.0
062 L000200 0.0
062 M000200 0.0
062 N000200 0.0
062 O000200 0.0
062 P000200 0.0
062 Q000200 0.0
062 R000200 0.3
063 A000200 73
063 B000200 0.0
064 A000200 N
070 A010200 Y
070 A020200 Y
070 B010200 N
070 B020200 N
070 C010200 N
070 C020200 N
070 D010200 N
070 D020200 N
070 E010200 N
070 E020200 N
070 F010200 N
070 F020200 N
070 G010200 N
070 G020200 N
070 H010200 N
070 H020200 N
070 I010200 N
070 I020200 N
070 J010200 Y
070 J020200 N
070 K010200 N
070 K020200 N
070 L010200 N
<PAGE> PAGE 10
070 L020200 N
070 M010200 N
070 M020200 N
070 N010200 Y
070 N020200 N
070 O010200 Y
070 O020200 N
070 P010200 Y
070 P020200 N
070 Q010200 N
070 Q020200 N
070 R010200 N
070 R020200 N
071 A000200 0
071 B000200 0
071 C000200 0
071 D000200 0
072 A000200 6
072 B000200 113939
072 C000200 0
072 D000200 0
072 E000200 0
072 F000200 266
072 G000200 2260
072 H000200 0
072 I000200 4295
072 J000200 31
072 K000200 0
072 L000200 36
072 M000200 4
072 N000200 0
072 O000200 0
072 P000200 0
072 Q000200 0
072 R000200 5
072 S000200 0
072 T000200 587
072 U000200 0
072 V000200 0
072 W000200 0
072 X000200 7484
072 Y000200 2
072 Z000200 106457
072AA000200 30
072BB000200 0
072CC010200 0
072CC020200 0
072DD010200 106457
072DD020200 0
072EE000200 0
073 A010200 0.0230
<PAGE> PAGE 11
073 A020200 0.0000
073 B000200 0.0000
073 C000200 0.0000
074 A000200 1
074 B000200 300818
074 C000200 4430643
074 D000200 0
074 E000200 0
074 F000200 0
074 G000200 0
074 H000200 0
074 I000200 721
074 J000200 0
074 K000200 0
074 L000200 33745
074 M000200 0
074 N000200 4765928
074 O000200 0
074 P000200 2079
074 Q000200 0
074 R010200 0
074 R020200 0
074 R030200 0
074 R040200 20567
074 S000200 0
074 T000200 4743282
074 U010200 4743293
074 U020200 0
074 V010200 1.00
074 V020200 0.00
074 W000200 1.0001
074 X000200 182506
074 Y000200 0
075 A000200 4549653
075 B000200 0
076 000200 0.00
SIGNATURE GARY P. SOURA
TITLE MANAGER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000106830
<NAME> VANGUARD MONEY MARKET RESERVES
<SERIES>
<NUMBER> 011
<NAME> VANGUARD PRIME MONEY MARKET FUND-INVESTOR SHARES
<MULTIPLIER> 1000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> NOV-30-1999
<PERIOD-START> DEC-01-1998
<PERIOD-END> MAY-31-1999
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 38334554
<INVESTMENTS-AT-VALUE> 38334554
<RECEIVABLES> 359994
<ASSETS-OTHER> 5643
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 38700191
<PAYABLE-FOR-SECURITIES> 50046
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 198682
<TOTAL-LIABILITIES> 248728
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 38451953
<SHARES-COMMON-STOCK> 37193641
<SHARES-COMMON-PRIOR> 33732899
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (490)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 37193174
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 936514
<OTHER-INCOME> 0
<EXPENSES-NET> 59653
<NET-INVESTMENT-INCOME> 876861
<REALIZED-GAINS-CURRENT> 33
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 876894
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 844084
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 26420059
<NUMBER-OF-SHARES-REDEEMED> 23769987
<SHARES-REINVESTED> 810671
<NET-CHANGE-IN-ASSETS> 3576136
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (523)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 2165
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 59661
<AVERAGE-NET-ASSETS> 35664580
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.024
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.024
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.33
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000106830
<NAME> VANGUARD MONEY MARKET RESERVES
<SERIES>
<NUMBER> 012
<NAME> VANGUARD PRIME MONEY MARKET FUND-INSTITUTIONAL SHARES
<MULTIPLIER> 1000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> NOV-30-1999
<PERIOD-START> DEC-01-1998
<PERIOD-END> MAY-31-1999
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 38334554
<INVESTMENTS-AT-VALUE> 38334554
<RECEIVABLES> 359994
<ASSETS-OTHER> 5643
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 38700191
<PAYABLE-FOR-SECURITIES> 50046
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 198682
<TOTAL-LIABILITIES> 248728
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 38451953
<SHARES-COMMON-STOCK> 1258309
<SHARES-COMMON-PRIOR> 1142949
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (490)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 1258289
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 936514
<OTHER-INCOME> 0
<EXPENSES-NET> 59653
<NET-INVESTMENT-INCOME> 876861
<REALIZED-GAINS-CURRENT> 33
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 876894
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 32777
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1626172
<NUMBER-OF-SHARES-REDEEMED> 1540343
<SHARES-REINVESTED> 29531
<NET-CHANGE-IN-ASSETS> 3576136
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (523)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 2165
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 59661
<AVERAGE-NET-ASSETS> 1335109
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.025
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.025
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.15
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000106830
<NAME> VANGUARD MONEY MARKET RESERVES
<SERIES>
<NUMBER> 02
<NAME> VANGUARD FEDERAL MONEY MARKET FUND
<MULTIPLIER> 1000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> NOV-30-1999
<PERIOD-START> DEC-01-1998
<PERIOD-END> MAY-31-1999
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 4731461
<INVESTMENTS-AT-VALUE> 4731461
<RECEIVABLES> 33746
<ASSETS-OTHER> 722
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 4765928
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 22646
<TOTAL-LIABILITIES> 22646
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 4743322
<SHARES-COMMON-STOCK> 4743293
<SHARES-COMMON-PRIOR> 4262943
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (40)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 4743282
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 113939
<OTHER-INCOME> 0
<EXPENSES-NET> 7482
<NET-INVESTMENT-INCOME> 106457
<REALIZED-GAINS-CURRENT> 30
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 106487
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 106457
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2478386
<NUMBER-OF-SHARES-REDEEMED> 2100401
<SHARES-REINVESTED> 102365
<NET-CHANGE-IN-ASSETS> 480380
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (70)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 266
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 7484
<AVERAGE-NET-ASSETS> 4549653
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.023
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.023
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.33
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
VANGUARD MONEY MARKET RESERVES
CIK No. 0000106830
File No. 811-2554
EXHIBIT INDEX
ITEM NO. 77.D POLICIES WITH RESPECT TO SECURITY INVESTMENTS
? Series 1 Vanguard Prime Money Market Fund
? As a result of Rule 2a-7 amendments, changes were made to the credit rating
requirements of unrated securities the Fund is permitted to purchase.
