WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000741375
<NAME> MAS FUNDS
<SERIES>
<NUMBER> 021
<NAME> FIXED INCOME PORTFOLIO, INSTITUTIONAL CLASS
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> SEP-30-2000
<PERIOD-START> OCT-01-1999
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<PAID-IN-CAPITAL-COMMON> 4,496,456
<SHARES-COMMON-STOCK> 363,311
<SHARES-COMMON-PRIOR> 385,361
<ACCUMULATED-NII-CURRENT> 83,032
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<OTHER-INCOME> 0
<EXPENSES-NET> (21,699)
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<REALIZED-GAINS-CURRENT> (95,763)
<APPREC-INCREASE-CURRENT> (88,079)
<NET-CHANGE-FROM-OPS> 309,318
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (295,280)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 69,172
<NUMBER-OF-SHARES-REDEEMED> (115,079)
<SHARES-REINVESTED> 23,857
<NET-CHANGE-IN-ASSETS> (223,562)
<ACCUMULATED-NII-PRIOR> 82,491
<ACCUMULATED-GAINS-PRIOR> (118,367)
<OVERDISTRIB-NII-PRIOR> 0
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<PER-SHARE-GAIN-APPREC> (0.02)
<PER-SHARE-DIVIDEND> (0.76)
<PER-SHARE-DISTRIBUTIONS> 0
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<PER-SHARE-NAV-END> 11.25
<EXPENSE-RATIO> 0.48
</TABLE>
