<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED
FROM THE SEMI-ANNUAL REPORT OF AMERICAN CENTURY GOVERNMENT INCOME
TRUST AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH REPORT.
</LEGEND>
<CIK> 0000773674
<NAME> AMERICAN CENTURY GOVERNMENT INCOME TRUST
<SERIES>
<NUMBER> 63
<NAME> LONG-TERM TREASURY FUND- ADVISOR CLASS
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> MAR-31-2000
<PERIOD-END> SEP-30-2000
<INVESTMENTS-AT-COST> 92,249,906
<INVESTMENTS-AT-VALUE> 96,481,624
<RECEIVABLES> 923,485
<ASSETS-OTHER> 1,396,199
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 98,801,308
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 66,819
<TOTAL-LIABILITIES> 66,819
<SENIOR-EQUITY> 3,943
<PAID-IN-CAPITAL-COMMON> 102,332,516
<SHARES-COMMON-STOCK> 394,345
<SHARES-COMMON-PRIOR> 479,436
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (7,833,688)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 4,231,718
<NET-ASSETS> 98,734,489
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 2,904,339
<OTHER-INCOME> 0
<EXPENSES-NET> 240,720
<NET-INVESTMENT-INCOME> 2,663,619
<REALIZED-GAINS-CURRENT> 289,932
<APPREC-INCREASE-CURRENT> 475,795
<NET-CHANGE-FROM-OPS> 3,429,346
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (119,333)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 122,816
<NUMBER-OF-SHARES-REDEEMED> (218,543)
<SHARES-REINVESTED> 10,636
<NET-CHANGE-IN-ASSETS> 8,140,651
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (823,964)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 228,419
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 240,720
<AVERAGE-NET-ASSETS> 4,292,988
<PER-SHARE-NAV-BEGIN> 9.82
<PER-SHARE-NII> 0.27
<PER-SHARE-GAIN-APPREC> 0.07
<PER-SHARE-DIVIDEND> (0.27)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 9.89
<EXPENSE-RATIO> 0.76
</TABLE>
