<PAGE> PAGE 1
000 B000000 02/29/2000
000 C000000 0000908406
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002 B000000 KANSAS CITY
002 C000000 MO
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002 D020000 7709
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
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007 C010100 1
007 C020100 PRIME MONEY MARKET FUND
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007 C010300 3
007 C010400 4
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007 C010700 7
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008 A00AA01 AMERICAN CENTURY INVESTMENT MANAGEMENT, INC.
008 B00AA01 A
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008 D01AA01 KANSAS CITY
008 D02AA01 MO
008 D03AA01 64111
008 D04AA01 7709
008 A00AA02 DELETE
010 A00AA01 AMERICAN CENTURY SERVICES CORPORATION
010 B00AA01 84-1406
010 C01AA01 KANSAS CITY
010 C02AA01 MO
010 C03AA01 64111
010 C04AA01 7709
010 A00AA02 FUNDS DISTRIBUTOR, INC.
010 B00AA02 8-20518
<PAGE> PAGE 2
010 C01AA02 BOSTON
010 C02AA02 MA
010 C03AA02 02109
011 A00AA01 FUNDS DISTRIBUTOR, INC.
011 B00AA01 8-20518
011 C01AA01 BOSTON
011 C02AA01 MA
011 C03AA01 02109
011 A00AA02 AMERICAN CENTURY INVESTMENT SERVICES, INC.
011 B00AA02 8-35220
011 C01AA02 KANSAS CITY
011 C02AA02 MO
011 C03AA02 64111
011 C04AA02 7709
012 A00AA01 AMERICAN CENTURY SERVICES CORPORATION
012 B00AA01 84-1406
012 C01AA01 KANSAS CITY
012 C02AA01 MO
012 C03AA01 64111
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013 A00AA01 PRICEWATERHOUSECOOPERS LLP
013 B01AA01 KANSAS CITY
013 B02AA01 MO
013 B03AA01 64105
013 B04AA01 2140
013 A00AA02 DELETE
014 A00AA01 AMERICAN CENTURY INVESTMENT SERVICES, INC.
014 B00AA01 8-35220
014 A00AA02 AMERICAN CENTURY BROKERAGE, INC.
014 B00AA02 8-50034
015 A00AA01 CHASE MANHATTAN BANK, N.A.
015 B00AA01 C
015 C01AA01 BROOKLYN
015 C02AA01 NY
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<PAGE> PAGE 3
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022 A000002 GOLDMAN SACHS & COMPANY
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022 C000002 1286969
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022 A000003 B.A. SECURITIES
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022 C000003 1250663
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022 C000004 1204286
022 D000004 20988
022 A000005 FIRST CHICAGO CAPITAL MARKETS
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022 C000007 730588
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022 A000008 MORGAN STANLEY & COMPANY
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022 C000008 564308
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022 C000009 557463
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022 C000010 358214
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023 D000000 182974
025 A00AA01 MERRILL LYNCH & COMPANY
025 B00AA01 13-2973073
025 C00AA01 D
025 D00AA01 47920
025 A00AA02 CHASE MANHATTAN BANK
025 C00AA02 D
025 D00AA02 15026
025 A00AA03 MORGAN STANLEY, DEAN WITTER
025 B00AA03 13-2655998
025 C00AA03 D
<PAGE> PAGE 4
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025 A00AA04 GENERAL ELECTRIC CAPITAL CORP.
025 B00AA04 13-1500700
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<PAGE> PAGE 5
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<PAGE> PAGE 6
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<PAGE> PAGE 7
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<PAGE> PAGE 8
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<PAGE> PAGE 10
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SIGNATURE MARYANNE ROEPKE
TITLE TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION
FROM THE ANNUAL REPORT OF AMERICAN CENTURY INVESTMENT
TRUST AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
REPORT.
</LEGEND>
<CIK> 0000908406
<NAME> PRIME MONEY MARKET FUND- INVESTOR CLASS
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> FEB-28-2000
<PERIOD-END> FEB-28-2000
<INVESTMENTS-AT-COST> 2,925,585,330
<INVESTMENTS-AT-VALUE> 2,925,585,330
<RECEIVABLES> 13,811,138
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2,939,396,468
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 12,772,786
<TOTAL-LIABILITIES> 12,772,786
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 0
<SHARES-COMMON-STOCK> 2,922,181,591
<SHARES-COMMON-PRIOR> 2,894,930,799
<ACCUMULATED-NII-CURRENT> (356,654)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 2,926,623,682
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 158,236,920
<OTHER-INCOME> 0
<EXPENSES-NET> 17,446,243
<NET-INVESTMENT-INCOME> 140,790,677
<REALIZED-GAINS-CURRENT> 0
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 71,528,515
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 140,590,132
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 4,383,800,939
<NUMBER-OF-SHARES-REDEEMED> 4,449,764,050
<SHARES-REINVESTED> 135,907,729
<NET-CHANGE-IN-ASSETS> 69,944,618
<ACCUMULATED-NII-PRIOR> (356,686)
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 17,330,691
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 17,446,243
<AVERAGE-NET-ASSETS> 2,919,756,773
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.05
<PER-SHARE-GAIN-APPREC> 0.00
<PER-SHARE-DIVIDEND> 0.05
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.60
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION
FROM THE ANNUAL REPORT OF AMERICAN CENTURY INVESTMENT
TRUST AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
REPORT.
</LEGEND>
<CIK> 0000908406
<NAME> AMERICAN CENTURY INVESTMENT TRUST
<SERIES>
<NUMBER> 13
<NAME> PRIME MONEY MARKET FUND - ADVISOR CLASS
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> FEB-28-2000
<PERIOD-END> FEB-28-2000
<INVESTMENTS-AT-COST> 2,925,585,330
<INVESTMENTS-AT-VALUE> 2,925,585,330
<RECEIVABLES> 13,811,138
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2,939,396,468
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 12,772,786
<TOTAL-LIABILITIES> 12,772,786
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 0
<SHARES-COMMON-STOCK> 4,798,745
<SHARES-COMMON-PRIOR> 3,795,129
<ACCUMULATED-NII-CURRENT> (356,654)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 2,926,623,682
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 158,236,920
<OTHER-INCOME> 0
<EXPENSES-NET> 17,446,243
<NET-INVESTMENT-INCOME> 140,790,677
<REALIZED-GAINS-CURRENT> 0
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 71,528,515
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 200,545
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 10,466,392
<NUMBER-OF-SHARES-REDEEMED> 9,080,972
<SHARES-REINVESTED> 198,445
<NET-CHANGE-IN-ASSETS> 69,944,618
<ACCUMULATED-NII-PRIOR> (356,686)
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 17,330,691
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 17,446,243
<AVERAGE-NET-ASSETS> 4,342,294
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.05
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<PER-SHARE-DIVIDEND> 0.05
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</TABLE>
Report of Independent Accountants
To the Trustees and Shareholders of the
American Century Prime Money Market Fund:
In planning and performing our audit of the financial statements and
financial highlights of the American Century Prime Money Market Fund (the
"Fund") for the year ended February 29, 2000, we considered its internal
control, including control activities for safeguarding securities, in order to
determine our auditing procedures for the purpose of expressing our opinion on
the financial statements and to comply with the requirements of Form N-SAR, not
to provide assurance on internal control.
The management of the Fund is responsible for establishing and maintaining
internal control. In fulfilling this responsibility, estimates and judgments by
management are required to assess the expected benefits and related costs of
controls. Generally, controls that are relevant to an audit pertain to the
entity's objective of preparing financial statements for external purposes that
are fairly presented in conformity with generally accepted accounting
principles. Those controls include the safeguarding of assets against
unauthorized acquisition, use or disposition.
Because of inherent limitations in internal control, errors or fraud may
occur and not be detected. Also, projection of any evaluation of internal
control to future periods is subject to the risk that controls may become
inadequate because of changes in conditions or that the effectiveness of their
design and operation may deteriorate.
Our consideration of internal control would not necessarily disclose all
matters in internal control that might be material weaknesses under standards
established by the American Institute of Certified Public Accountants. A
material weakness is a condition in which the design or operation of one or more
of the internal control components does not reduce to a relatively low level the
risk that misstatements caused by error or fraud in amounts that would be
material in relation to the financial statements being audited may occur and not
be detected within a timely period by employees in the normal course of
performing their assigned functions. However, we noted no matters involving
internal control and its operation, including controls for safeguarding
securities that we consider to be material weaknesses as defined above as of
February 29, 2000.
This report is intended solely for the information and use of the Board of
Directors, management and the Securities and Exchange Commission and is not
intended to be and should not be used by anyone other than these specified
parties.
March 31, 2000
