<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> 13
<NAME> GNMA FUND ADVISOR CLASS
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> MAR-31-2000
<PERIOD-END> SEP-30-2000
<INVESTMENTS-AT-COST> 1,285,788,719
<INVESTMENTS-AT-VALUE> 1,272,640,519
<RECEIVABLES> 9,480,183
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1,282,120,702
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2,008,483
<TOTAL-LIABILITIES> 2,008,483
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,330,279,335
<SHARES-COMMON-STOCK> 1,631,552
<SHARES-COMMON-PRIOR> 1,287,153
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (37,018,916)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (13,148,200)
<NET-ASSETS> 1,280,112,219
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 45,638,637
<OTHER-INCOME> 0
<EXPENSES-NET> 3,713,042
<NET-INVESTMENT-INCOME> 41,925,595
<REALIZED-GAINS-CURRENT> (2,836,881)
<APPREC-INCREASE-CURRENT> 19,348,375
<NET-CHANGE-FROM-OPS> 58,437,089
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (469,882)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 581,456
<NUMBER-OF-SHARES-REDEEMED> (280,157)
<SHARES-REINVESTED> 43,100
<NET-CHANGE-IN-ASSETS> 27,028,818
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (21,556,755)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3,656,093
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 3,713,042
<AVERAGE-NET-ASSETS> 14,560,469
<PER-SHARE-NAV-BEGIN> 10.16
<PER-SHARE-NII> 0.33
<PER-SHARE-GAIN-APPREC> 0.14
<PER-SHARE-DIVIDEND> (0.33)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 10.30
<EXPENSE-RATIO> 0.84
</TABLE>
