<PAGE> PAGE 1
000 B000000 02/28/99
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000 F000000 Y
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<PAGE> PAGE 2
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010 A000801 MASSACHUSETTS MUTUAL LIFE INSURANCE COMPANY
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<PAGE> PAGE 3
010 C010802 BOSTON
010 C020802 MA
010 C030802 02116
011 A000801 OPPENHEIMERFUNDS DISTRIBUTOR, INC.
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011 C010801 NEW YORK
011 C020801 NY
011 C030801 10048
011 A000802 MML INVESTORS SERVICES, INC.
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011 C010802 SPRINGFIELD
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012 A000801 INVESTORS BANK & TRUST COMPANY
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012 C010801 BOSTON
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013 A000801 DELOITTE & TOUCHE LLP
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014 A000803 CENTENNIAL ASSET MANAGEMENT CORPORATION
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014 A000805 BABSON SECURITIES, CORP.
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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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<PAGE> PAGE 8
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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 year ended February 28, 1999
and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<SERIES>
<NUMBER> 31
<NAME> Indexed Equity Fund, Class A
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> FEB-28-1999
<PERIOD-END> FEB-28-1999
<INVESTMENTS-AT-COST> 0
<INVESTMENTS-AT-VALUE> 426,835,528
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<TOTAL-LIABILITIES> 584,840
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<SHARES-COMMON-STOCK> 10,026
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<OVERDISTRIBUTION-GAINS> 0
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<NET-ASSETS> 118,393
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<EXPENSES-NET> 1,157
<NET-INVESTMENT-INCOME> (26)
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<APPREC-INCREASE-CURRENT> 14,841
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<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 306
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 10,000
<NUMBER-OF-SHARES-REDEEMED> 0
<SHARES-REINVESTED> 26
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<ACCUMULATED-NII-PRIOR> 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 year ended February 28, 1999
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> 12-MOS
<FISCAL-YEAR-END> FEB-28-1999
<PERIOD-END> FEB-28-1999
<INVESTMENTS-AT-COST> 0
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<OVERDISTRIBUTION-GAINS> 0
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<NET-INVESTMENT-INCOME> 6,907
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<DISTRIBUTIONS-OF-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 year ended February 28, 1999
and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<SERIES>
<NUMBER> 33
<NAME> Indexed Equity Fund, Class S
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> FEB-28-1999
<PERIOD-END> FEB-28-1999
<INVESTMENTS-AT-COST> 0
<INVESTMENTS-AT-VALUE> 426,835,528
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<SHARES-COMMON-PRIOR> 0
<ACCUMULATED-NII-CURRENT> 631,540
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 2,030,590
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 37,578,723
<NET-ASSETS> 426,686,755
<DIVIDEND-INCOME> 3,324,627
<INTEREST-INCOME> 751,937
<OTHER-INCOME> 0
<EXPENSES-NET> 1,046,309
<NET-INVESTMENT-INCOME> 3,030,255
<REALIZED-GAINS-CURRENT> 2,033,962
<APPREC-INCREASE-CURRENT> 37,502,486
<NET-CHANGE-FROM-OPS> 42,566,703
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 2,399,425
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 46,076,164
<NUMBER-OF-SHARES-REDEEMED> 10,192,698
<SHARES-REINVESTED> 202,483
<NET-CHANGE-IN-ASSETS> 426,686,755
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
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<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,048,763
<AVERAGE-NET-ASSETS> 247,993,280
<PER-SHARE-NAV-BEGIN> 10.00
<PER-SHARE-NII> 0.13
<PER-SHARE-GAIN-APPREC> 1.78
<PER-SHARE-DIVIDEND> 0.00
<PER-SHARE-DISTRIBUTIONS> (0.09)
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 11.82
<EXPENSE-RATIO> 0.43
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0.00
</TABLE>
INDEPENDENT
AUDITORS' REPORT
To the Trustees and Shareholders of MassMutual Indexed Equity Fund:
In planning and performing our audit of the financial statements of MassMutual
Indexed Equity Fund (the "Fund"), a series of the MassMutual Institutional Funds
(the "Trust") for the year ended February 28, 1999 (on which we have issued our
report dated April 8, 1999), we considered its internal control in order to
determine our auditing procedures for the purpose of expressing our opinion on
the financial statements and to comply with the requirements of Form N-SAR, and
not to provide assurance on the Trust's internal control.
The management of the Trust is responsible for establishing and maintaining
internal control. In fulfilling this responsibility, estimates and judgments by
management are required to assess the expected benefits and related costs of
controls. Generally, controls that are relevant to an audit pertain to the
entity's objective of preparing financial statements for external purposes that
are fairly presented in conformity with generally accepted accounting
principles. Those controls include the safeguarding of assets against
unauthorized acquisition, use, or disposition.
Because of inherent limitations in any internal control, misstatements due to
error or fraud may occur and not be detected. Also, projections of any
evaluation of internal control to future periods are subject to the risk that
the internal control may become inadequate because of changes in conditions or
that the degree of compliance with policies or procedures deteriorate.
Our consideration of the Trust's internal control would not necessarily disclose
all matters in internal control that might be material weaknesses under
standards established by the American Institute of Certified Public Accountants.
A material weakness is a condition in which the design or operation of one or
more of the internal control components does not reduce to a relatively low
level the risk that misstatements error or fraud in amounts that would be
material in relation to the financial statements being audited may occur and not
be detected within a timely period by employees in the normal course of
performing their assigned functions. However, we noted no matters involving the
Trust's internal control and its operation that we consider to be material
weaknesses as defined above as of February 28, 1999.
This report is intended solely for the information and use of management, the
Board of Trustees of MassMutual Institutional Funds, and the Securities and
Exchange Commission and is not intended to be and should not be used by anyone
other than these specified parties.
DELOITTE & TOUCHE LLP
April 8, 1999
