<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000741375
<NAME> MAS FUNDS
<SERIES>
<NUMBER> 223
<NAME> BALANCED PORTFOLIO, ADVISER CLASS
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> SEP-30-2000
<PERIOD-START> OCT-01-1999
<PERIOD-END> SEP-30-2000
<INVESTMENTS-AT-COST> 481,031
<INVESTMENTS-AT-VALUE> 513,279
<RECEIVABLES> 134,270
<ASSETS-OTHER> 42
<OTHER-ITEMS-ASSETS> 17,230
<TOTAL-ASSETS> 664,821
<PAYABLE-FOR-SECURITIES> 100,174
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 17,556
<TOTAL-LIABILITIES> 117,730
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 489,174
<SHARES-COMMON-STOCK> 2,544
<SHARES-COMMON-PRIOR> 2,117
<ACCUMULATED-NII-CURRENT> 3,691
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 21,404
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 32,822
<NET-ASSETS> 547,091
<DIVIDEND-INCOME> 1,885
<INTEREST-INCOME> 13,647
<OTHER-INCOME> 0
<EXPENSES-NET> (2,365)
<NET-INVESTMENT-INCOME> 13,167
<REALIZED-GAINS-CURRENT> 24,317
<APPREC-INCREASE-CURRENT> 16,268
<NET-CHANGE-FROM-OPS> 53,752
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (964)
<DISTRIBUTIONS-OF-GAINS> (4,100)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 555
<NUMBER-OF-SHARES-REDEEMED> (524)
<SHARES-REINVESTED> 396
<NET-CHANGE-IN-ASSETS> 175,787
<ACCUMULATED-NII-PRIOR> 3,741
<ACCUMULATED-GAINS-PRIOR> 46,950
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,809
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,402
<AVERAGE-NET-ASSETS> 401,751
<PER-SHARE-NAV-BEGIN> 13.80
<PER-SHARE-NII> 0.41
<PER-SHARE-GAIN-APPREC> 1.44
<PER-SHARE-DIVIDEND> (0.42)
<PER-SHARE-DISTRIBUTIONS> (1.89)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 13.34
<EXPENSE-RATIO> 0.83
</TABLE>