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<PAGE> PAGE 2
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<PAGE> PAGE 3
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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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<PAGE> PAGE 9
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<PAGE> PAGE 10
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<PAGE> PAGE 11
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<PAGE> PAGE 12
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<PAGE> PAGE 13
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<PAGE> PAGE 14
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<PAGE> PAGE 15
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<PAGE> PAGE 16
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<PAGE> PAGE 18
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<PAGE> PAGE 19
SIGNATURE WILLIAM H. KEOUGH
TITLE TREASURER
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<NET-ASSETS> 172330979
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 4994201
<OTHER-INCOME> 0
<EXPENSES-NET> 672670
<NET-INVESTMENT-INCOME> 4321531
<REALIZED-GAINS-CURRENT> (639)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 4320892
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 4321531<F3>
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 312406316<F4>
<NUMBER-OF-SHARES-REDEEMED> 317181682<F5>
<SHARES-REINVESTED> 3911780<F6>
<NET-CHANGE-IN-ASSETS> (864225)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (275424)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 334046
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 941461
<AVERAGE-NET-ASSETS> 169175859<F7>
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.03<F8>
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.03<F9>
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.80<F10>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>shares-coomon-stock per class:
class a - 169533050
class b - 3073992
<F2>represents class a shares only; class b shares were offered subsequent to
fiscal year-end 1994.
<F3>distributions-of-income per class:
class a - $4299196
class b - $22335
<F4>number-of-shares-sold per class:
class a - 306827516
class b - 5578800
<F5>number-of-shares-redeemed per class:
class a - 314657890
class b - 2523792
<F6>shares-reinvested per class:
class a - 3892796
class b - 18984
<F7>average-net-assets per class:
class a - 167301731
class b - 1874128
<F8>represents per-share-nii for class a shares; per-share-nii for class b
shares is $0.01.
<F9>represents per-share-dividend for class a shares; per-share-dividend for
class b shares is $0.01.
<F10>represents expense-ratio for class a shares; expense-ratio for class b
shares is 1.52.
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000812195
<NAME> PIONEER MONEY MARKET TRUST
<SERIES>
<NUMBER> 2
<NAME> PIONEER U.S. GOVERNMENT MONEY FUND
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1995
<PERIOD-END> JUN-30-1995
<INVESTMENTS-AT-COST> 31542544
<INVESTMENTS-AT-VALUE> 31542544
<RECEIVABLES> 254199
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 5382
<TOTAL-ASSETS> 31802125
<PAYABLE-FOR-SECURITIES> 2000000
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 194856
<TOTAL-LIABILITIES> 2194856
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 29607269
<SHARES-COMMON-STOCK> 29607269
<SHARES-COMMON-PRIOR> 29100579
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 29607269
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 875905
<OTHER-INCOME> 0
<EXPENSES-NET> 107641
<NET-INVESTMENT-INCOME> 768264
<REALIZED-GAINS-CURRENT> 0
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 768264
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 768264
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 52064768
<NUMBER-OF-SHARES-REDEEMED> 52258131
<SHARES-REINVESTED> 700053
<NET-CHANGE-IN-ASSETS> 506690
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 58835
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 180051
<AVERAGE-NET-ASSETS> 29616139
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.03
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.03
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.73
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000812195
<NAME> PIONEER MONEY MARKET TRUST
<SERIES>
<NUMBER> 3
<NAME> PIONEER TAX-FREE MONEY FUND
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1995
<PERIOD-END> JUN-30-1995
<INVESTMENTS-AT-COST> 6950442
<INVESTMENTS-AT-VALUE> 6950442
<RECEIVABLES> 79266
<ASSETS-OTHER> 4177
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 7033885
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 23737
<TOTAL-LIABILITIES> 23737
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 7010148
<SHARES-COMMON-STOCK> 7010148
<SHARES-COMMON-PRIOR> 10059008
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 7010148
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 146479
<OTHER-INCOME> 0
<EXPENSES-NET> 23876
<NET-INVESTMENT-INCOME> 122603
<REALIZED-GAINS-CURRENT> 0
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 122603
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 122603
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 7784575
<NUMBER-OF-SHARES-REDEEMED> 10941861
<SHARES-REINVESTED> 108426
<NET-CHANGE-IN-ASSETS> (3048860)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 15387
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 78724
<AVERAGE-NET-ASSETS> 7776973
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.02
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.02
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.62
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
