<PAGE> PAGE 1
000 A000000 08/31/98
000 C000000 0000916053
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001 A000000 MASSMUTUAL INSTITUTIONAL FUNDS
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002 B000000 SPRINGFIELD
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<PAGE> PAGE 2
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010 A000801 MASSACHUSETTS MUTUAL LIFE INSURANCE COMPANY
010 B000801 801-8059
010 C010801 SPRINGFIELD
010 C020801 MA
010 C030801 01111
010 C040801 0001
010 A000802 INVESTORS BANK & TRUST COMPANY (SUBADM)
010 B000802 85-720
010 C010802 BOSTON
010 C020802 MA
010 C030802 02116
011 A000801 OPPENHEIMERFUNDS DISTRIBUTOR, INC.
011 B000801 8-22992
011 C010801 NEW YORK
011 C020801 NY
011 C030801 10048
011 A000802 MML INVESTORS SERVICES, INC.
011 B000802 8-27250
011 C010802 SPRINGFIELD
011 C020802 MA
011 C030802 01144
012 A000801 INVESTORS BANK & TRUST COMPANY
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<PAGE> PAGE 3
012 C010801 BOSTON
012 C020801 MA
012 C030801 02116
013 A000801 PRICEWATERHOUSECOOPERS LLP
013 B010801 SPRINGFIELD
013 B020801 MA
013 B030801 01101
013 B040801 0059
014 A000801 MML INVESTORS SERVICES, INC.
014 B000801 8-27250
014 A000802 OPPENHEIMERFUNDS DISTRIBUTOR, INC.
014 B000802 8-22992
014 A000803 CENTENNIAL ASSET MANAGEMENT CORPORATION
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014 A000804 MULTI SOURCE SERVICES, INC.
014 B000804 8-40450
014 A000805 BABSON SECURITIES, CORP.
014 B000805 8-47589
015 A000801 INVESTORS BANK & TRUST COMPANY
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<PAGE> PAGE 4
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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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SIGNATURE
TITLE
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information
extracted from The MassMutual Institutional Funds, Inc
form N-SAR for the period ended August 31, 1998
and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<SERIES>
<NUMBER> 31
<NAME> Indexed Equity Fund, Class A
<S> <C>
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<FISCAL-YEAR-END> FEB-28-1999
<PERIOD-END> Aug-31-1998
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<TOTAL-LIABILITIES> 1,277,462
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<SHARES-COMMON-STOCK> 10,000
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<OVERDISTRIBUTION-GAINS> 0
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</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information
extracted from The MassMutual Institutional Funds, Inc
form N-SAR for the period ended August 31, 1998
and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<SERIES>
<NUMBER> 32
<NAME> Indexed Equity Fund, Class Y
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> FEB-28-1999
<PERIOD-END> Aug-31-1998
<INVESTMENTS-AT-COST> 0
<INVESTMENTS-AT-VALUE> 206,858,607
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</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information
extracted from The MassMutual Institutional Funds, Inc
form N-SAR for the period ended August 31, 1998
and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<SERIES>
<NUMBER> 33
<NAME> Indexed Equity Fund, Class S
<S> <C>
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<FISCAL-YEAR-END> FEB-28-1999
<PERIOD-END> Aug-31-1998
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</TABLE>
