<PAGE> PAGE 1
000 A000000 07/31/95
000 C000000 0000225604
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 A
001 A000000 MFS SERIES TRUST III
001 B000000 811-2794
001 C000000 6179545000
002 A000000 500 BOYLSTON STREET
002 B000000 BOSTON
002 C000000 MA
002 D010000 02116
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 2
007 C010100 1
007 C020100 MFS HIGH INCOME FUND
007 C030100 N
007 C010200 2
007 C020200 MFS MUNICIPAL HIGH INCOME FUND
007 C030200 N
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A00AA01 MASSACHUSETTS FINANCIAL SERVICE COMPANY
008 B00AA01 A
008 C00AA01 801-17352
008 D01AA01 BOSTON
008 D02AA01 MA
008 D03AA01 02116
011 A00AA01 MFS FUND DISTRIBUTORS, INC.
011 B00AA01 8-27864
011 C01AA01 BOSTON
011 C02AA01 MA
011 C03AA01 02116
012 A00AA01 MFS SERVICE CENTER, INC.
012 B00AA01 84-1316
012 C01AA01 BOSTON
012 C02AA01 MA
<PAGE> PAGE 2
012 C03AA01 02116
018 00AA00 Y
019 A00AA00 Y
019 B00AA00 50
019 C00AA00 MASSFINSER
020 A000001 INSTINET CORP.
020 B000001 13-3443395
020 C000001 3
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 3
022 A000001 LEHMAN BROTHERS
022 B000001 13-2518466
022 C000001 333123
022 D000001 79278
022 A000002 CHEMICAL BANK
022 B000002 13-4994650
022 C000002 150836
022 D000002 4283
022 A000003 PAINEWEBBER INCORPORATED
022 B000003 13-2638166
022 C000003 74457
022 D000003 75130
022 A000004 BANK OF AMERICA
022 B000004 94-1687665
022 C000004 141121
022 D000004 997
022 A000005 GOLDMAN SACHS & COMPANY
022 B000005 13-5108880
022 C000005 87125
022 D000005 31067
022 A000006 MERRILL LYNCH
022 B000006 13-5674085
022 C000006 81004
022 D000006 29260
022 A000007 CS FIRST BOSTON
022 B000007 13-5659485
022 C000007 91064
022 D000007 8469
022 A000008 FORD MOTOR CREDIT CO.
022 B000008 38-1612444
022 C000008 84454
022 D000008 0
022 A000009 J.P. MORGAN SECURITIES
<PAGE> PAGE 3
022 B000009 13-3224016
022 C000009 54949
022 D000009 26049
022 A000010 FIRST CHICAGO
022 B000010 36-0899825
022 C000010 78582
022 D000010 0
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026 G020000 N
026 H000000 N
027 000000 Y
054 A00AA00 Y
054 B00AA00 Y
054 C00AA00 N
054 D00AA00 N
054 E00AA00 N
054 F00AA00 N
054 G00AA00 N
054 H00AA00 Y
054 I00AA00 N
054 J00AA00 Y
054 K00AA00 N
054 L00AA00 N
054 M00AA00 Y
054 N00AA00 N
054 O00AA00 N
066 A00AA00 N
067 00AA00 N
068 A00AA00 N
068 B00AA00 N
069 00AA00 N
077 A000000 N
078 000000 N
080 A00AA00 NATIONAL UNION INSURANCE CO.
080 B00AA00 ICI MUTUAL
080 C00AA00 60000
081 A00AA00 Y
081 B00AA00 75
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083 A00AA00 N
083 B00AA00 0
084 A00AA00 N
<PAGE> PAGE 4
084 B00AA00 0
085 A00AA00 Y
085 B00AA00 N
013 A000101 DELOITTE & TOUCHE
013 B010101 BOSTON
013 B020101 MA
013 B030101 02110
015 A000101 STATE STREET BANK AND TRUST COMPANY
015 B000101 C
015 C010101 BOSTON
015 C020101 MA
015 C030101 02110
015 E010101 X
015 A000102 CHASE MANHATTAN BANK, N.A.
015 B000102 C
015 C010102 NEW YORK
015 C020102 NY
015 C030102 10081
015 E040102 X
024 000100 N
028 A010100 54767
028 A020100 3507
028 A030100 0
028 A040100 20948
028 B010100 28527
028 B020100 3526
028 B030100 0
028 B040100 28821
028 C010100 25908
028 C020100 3509
028 C030100 0
028 C040100 26621
028 D010100 32284
028 D020100 3596
028 D030100 0
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028 F010100 54411
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028 F040100 67848
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028 G020100 20883
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028 G040100 258951
028 H000100 36663
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<PAGE> PAGE 5
030 B000100 4.75
030 C000100 0.00
031 A000100 63
031 B000100 0
032 000100 323
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036 A000100 N
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037 000100 N
038 000100 0
039 000100 N
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041 000100 Y
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042 B000100 0
042 C000100 1
042 D000100 99
042 E000100 0
042 F000100 0
042 G000100 0
042 H000100 0
043 000100 2419
044 000100 0
045 000100 Y
046 000100 N
047 000100 N
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048 A010100 0
048 A020100 0.000
048 B010100 0
048 B020100 0.000
048 C010100 0
048 C020100 0.000
048 D010100 0
048 D020100 0.000
048 E010100 0
048 E020100 0.000
048 F010100 0
048 F020100 0.000
048 G010100 0
048 G020100 0.000
048 H010100 0
048 H020100 0.000
048 I010100 0
048 I020100 0.000
048 J010100 0
048 J020100 0.000
048 K010100 0
048 K020100 0.000
<PAGE> PAGE 6
049 000100 N
050 000100 Y
051 000100 N
052 000100 N
053 A000100 Y
053 B000100 N
053 C000100 Y
055 A000100 N
055 B000100 N
056 000100 Y
057 000100 N
058 A000100 N
059 000100 Y
060 A000100 Y
060 B000100 Y
061 000100 1000
062 A000100 Y
062 B000100 0.0
062 C000100 2.9
062 D000100 0.0
062 E000100 0.0
062 F000100 0.0
062 G000100 0.0
062 H000100 0.0
062 I000100 0.0
062 J000100 0.0
062 K000100 0.0
062 L000100 0.0
062 M000100 0.0
062 N000100 0.0
062 O000100 0.0
062 P000100 85.7
062 Q000100 0.0
062 R000100 6.1
063 A000100 0
063 B000100 7.9
064 A000100 N
070 A010100 Y
070 A020100 Y
070 B010100 N
070 B020100 N
070 C010100 Y
070 C020100 N
070 D010100 N
070 D020100 N
070 E010100 Y
070 E020100 N
070 F010100 N
070 F020100 N
070 G010100 Y
070 G020100 N
<PAGE> PAGE 7
070 H010100 N
070 H020100 N
070 I010100 N
070 I020100 N
070 J010100 Y
070 J020100 Y
070 K010100 Y
070 K020100 N
070 L010100 Y
070 L020100 Y
070 M010100 Y
070 M020100 Y
070 N010100 Y
070 N020100 N
070 O010100 Y
070 O020100 N
070 P010100 Y
070 P020100 N
070 Q010100 N
070 Q020100 N
070 R010100 N
070 R020100 N
071 A000100 239120
071 B000100 207512
071 C000100 814038
071 D000100 25
072 A000100 6
072 B000100 43431
072 C000100 0
072 D000100 0
072 E000100 0
072 F000100 1998
072 G000100 0
072 H000100 0
072 I000100 782
072 J000100 63
072 K000100 38
072 L000100 63
072 M000100 26
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072 S000100 45
072 T000100 2419
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<PAGE> PAGE 8
072 Z000100 37765
072AA000100 0
072BB000100 29624
072CC010100 84938
072CC020100 0
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072DD020100 11896
072EE000100 0
073 A010100 0.2200
073 A020100 0.2000
073 B000100 0.0000
073 C000100 0.0000
074 A000100 32
074 B000100 0
074 C000100 25520
074 D000100 802776
074 E000100 22892
074 F000100 9620
074 G000100 0
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074 J000100 7403
074 K000100 1090
074 L000100 19676
074 M000100 11
074 N000100 889018
074 O000100 3008
074 P000100 1086
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074 R030100 0
074 R040100 2937
074 S000100 0
074 T000100 881987
074 U010100 170682
074 U020100 54633
074 V010100 5.17
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074 W000100 0.0000
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075 B000100 874101
076 000100 0.00
013 A000201 ERNST & YOUNG LLP
013 B010201 BOSTON
013 B020201 MA
013 B030201 02116
013 B040201 5072
015 A000201 STATE STREET BANK AND TRUST COMPANY
<PAGE> PAGE 9
015 B000201 C
015 C010201 BOSTON
015 C020201 MA
015 C030201 02110
015 E010201 X
015 A000202 BANK OF NEW YORK
015 B000202 S
015 C010202 NEW YORK
015 C020202 NY
015 C030202 10286
015 E010202 X
015 A000203 CHEMICAL BANK
015 B000203 S
015 C010203 NEW YORK
015 C020203 NY
015 C030203 10041
015 E010203 X
015 A000204 MORGAN GUARANTY TRUST COMPANY
015 B000204 S
015 C010204 NEW YORK
015 C020204 NY
015 C030204 10015
015 E010204 X
015 A000205 BANKERS TRUST COMPANY
015 B000205 S
015 C010205 NEW YORK
015 C020205 NY
015 C030205 10015
015 E010205 X
024 000200 N
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<PAGE> PAGE 10
028 F020200 2299
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<PAGE> PAGE 11
048 G010200 0
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055 A000200 N
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056 000200 Y
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<PAGE> PAGE 12
070 C010200 Y
070 C020200 N
070 D010200 N
070 D020200 N
070 E010200 Y
070 E020200 N
070 F010200 N
070 F020200 N
070 G010200 Y
070 G020200 N
070 H010200 N
070 H020200 N
070 I010200 N
070 I020200 N
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070 J020200 Y
070 K010200 Y
070 K020200 N
070 L010200 N
070 L020200 N
070 M010200 N
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<PAGE> PAGE 13
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<PAGE> PAGE 14
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SIGNATURE JAMES O. YOST
TITLE ASSISTANT TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION
EXTRACTED FROM THE FINANCIAL STATEMENTS OF MFS HIGH INCOME
FUND CLASS A AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
<NUMBER>011
<NAME> MFS HIGH INCOME FUND CLASS A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1996
<PERIOD-END> JUL-31-1995
<INVESTMENTS-AT-COST> 864,279,316
<INVESTMENTS-AT-VALUE> 860,806,634
<RECEIVABLES> 28,168,198
<ASSETS-OTHER> 10,854
<OTHER-ITEMS-ASSETS> 32,470
<TOTAL-ASSETS> 889,018,156
<PAYABLE-FOR-SECURITIES> 3,007,800
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4,023,084
<TOTAL-LIABILITIES> 7,030,884
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,163,893,795
<SHARES-COMMON-STOCK> 114,533,627
<SHARES-COMMON-PRIOR> 108,084,812
<ACCUMULATED-NII-CURRENT> 842,399
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 279,281,788
<ACCUM-APPREC-OR-DEPREC> (3,467,134)
<NET-ASSETS> 881,987,272
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 43,430,759
<OTHER-INCOME> 0
<EXPENSES-NET> 5,665,487
<NET-INVESTMENT-INCOME> 37,765,272
<REALIZED-GAINS-CURRENT> (29,623,636)
<APPREC-INCREASE-CURRENT> 84,934,938
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<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (24,657,590)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 26,160,711
<NUMBER-OF-SHARES-REDEEMED> 22,622,869
<SHARES-REINVESTED> 2,910,973
<NET-CHANGE-IN-ASSETS> 69,134,800
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 62,774
<OVERDIST-NET-GAINS-PRIOR> 249,658,152
<GROSS-ADVISORY-FEES> 1,998,301
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5,950,142
<AVERAGE-NET-ASSETS> 874,101,058
<PER-SHARE-NAV-BEGIN> 4.84
<PER-SHARE-NII> 0.23
<PER-SHARE-GAIN-APPREC> 0.32
<PER-SHARE-DIVIDEND> (0.22)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 5.17
<EXPENSE-RATIO> 1.01
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION
EXTRACTED FROM THE FINANCIAL STATEMENTS OF MFS HIGH INCOME
FUND CLASS B AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
<NUMBER>012
<NAME> MFS HIGH INCOME FUND CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1996
<PERIOD-END> JUL-31-1995
<INVESTMENTS-AT-COST> 864,279,316
<INVESTMENTS-AT-VALUE> 860,806,634
<RECEIVABLES> 28,168,198
<ASSETS-OTHER> 10,854
<OTHER-ITEMS-ASSETS> 32,470
<TOTAL-ASSETS> 889,018,156
<PAYABLE-FOR-SECURITIES> 3,007,800
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4,023,084
<TOTAL-LIABILITIES> 7,030,884
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,163,893,795
<SHARES-COMMON-STOCK> 54,632,756
<SHARES-COMMON-PRIOR> 58,992,349
<ACCUMULATED-NII-CURRENT> 842,399
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 279,281,788
<ACCUM-APPREC-OR-DEPREC> (3,467,134)
<NET-ASSETS> 881,987,272
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 43,430,759
<OTHER-INCOME> 0
<EXPENSES-NET> 5,665,487
<NET-INVESTMENT-INCOME> 37,765,272
<REALIZED-GAINS-CURRENT> (29,623,636)
<APPREC-INCREASE-CURRENT> 84,934,938
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<DISTRIBUTIONS-OF-INCOME> (11,895,889)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 21,574,992
<NUMBER-OF-SHARES-REDEEMED> 27,125,410
<SHARES-REINVESTED> 1,190,825
<NET-CHANGE-IN-ASSETS> 69,134,800
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 62,774
<OVERDIST-NET-GAINS-PRIOR> 249,658,152
<GROSS-ADVISORY-FEES> 1,998,301
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5,950,142
<AVERAGE-NET-ASSETS> 874,101,058
<PER-SHARE-NAV-BEGIN> 4.84
<PER-SHARE-NII> 0.20
<PER-SHARE-GAIN-APPREC> 0.33
<PER-SHARE-DIVIDEND> (0.20)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 5.17
<EXPENSE-RATIO> 0.00
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION
EXTRACTED FROM THE FINANCIAL STATEMENTS OF MFS HIGH INCOME
FUND CLASS C AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
<NUMBER>013
<NAME> MFS HIGH INCOME FUND CLASS C
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1996
<PERIOD-END> JUL-31-1995
<INVESTMENTS-AT-COST> 864,279,316
<INVESTMENTS-AT-VALUE> 860,806,634
<RECEIVABLES> 28,168,198
<ASSETS-OTHER> 10,854
<OTHER-ITEMS-ASSETS> 32,470
<TOTAL-ASSETS> 889,018,156
<PAYABLE-FOR-SECURITIES> 3,007,800
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4,023,084
<TOTAL-LIABILITIES> 7,030,884
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,163,893,795
<SHARES-COMMON-STOCK> 1,516,033
<SHARES-COMMON-PRIOR> 706,226
<ACCUMULATED-NII-CURRENT> 842,399
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 279,281,788
<ACCUM-APPREC-OR-DEPREC> (3,467,134)
<NET-ASSETS> 881,987,272
<DIVIDEND-INCOME> 0
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<OTHER-INCOME> 0
<EXPENSES-NET> 5,665,487
<NET-INVESTMENT-INCOME> 37,765,272
<REALIZED-GAINS-CURRENT> (29,623,636)
<APPREC-INCREASE-CURRENT> 84,934,938
<NET-CHANGE-FROM-OPS> 93,076,574
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (306,620)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2,239,257
<NUMBER-OF-SHARES-REDEEMED> 1,467,523
<SHARES-REINVESTED> 38,073
<NET-CHANGE-IN-ASSETS> 69,134,800
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 62,774
<OVERDIST-NET-GAINS-PRIOR> 249,658,152
<GROSS-ADVISORY-FEES> 1,998,301
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5,950,142
<AVERAGE-NET-ASSETS> 874,101,058
<PER-SHARE-NAV-BEGIN> 4.85
<PER-SHARE-NII> 0.22
<PER-SHARE-GAIN-APPREC> 0.30
<PER-SHARE-DIVIDEND> (0.20)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 5.17
<EXPENSE-RATIO> 0.00
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
THE FINANCIAL STATEMENTS OF MASSACHUSETTS FINANCIAL SERVICES AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
<NUMBER> 021
<NAME> MFS MUNICIPAL HIGH INCOME FUND-CLASS A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1996
<PERIOD-END> JUL-31-1995
<INVESTMENTS-AT-COST> 1,004,843,021
<INVESTMENTS-AT-VALUE> 1,032,625,013
<RECEIVABLES> 26,323,995
<ASSETS-OTHER> 13,101
<OTHER-ITEMS-ASSETS> 41,410
<TOTAL-ASSETS> 1,059,003,519
<PAYABLE-FOR-SECURITIES> 355,042
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 5,779,242
<TOTAL-LIABILITIES> 6,134,284
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,119,640,034
<SHARES-COMMON-STOCK> 110,914,251
<SHARES-COMMON-PRIOR> 107,020,050
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> (1,431,578)
<ACCUMULATED-NET-GAINS> (93,121,213)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 27,781,992
<NET-ASSETS> 1,052,869,235
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 40,208,973
<OTHER-INCOME> 0
<EXPENSES-NET> 5,062,509
<NET-INVESTMENT-INCOME> 35,146,464
<REALIZED-GAINS-CURRENT> (14,333,711)
<APPREC-INCREASE-CURRENT> 48,347,919
<NET-CHANGE-FROM-OPS> 69,160,672
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (35,672,235)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 9,112,825
<NUMBER-OF-SHARES-REDEEMED> (6,726,876)
<SHARES-REINVESTED> 1,508,252
<NET-CHANGE-IN-ASSETS> 77,151,388
<ACCUMULATED-NII-PRIOR> 1,098,869
<ACCUMULATED-GAINS-PRIOR> (79,164,299)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3,342,223
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5,062,509
<AVERAGE-NET-ASSETS> 973,043,822
<PER-SHARE-NAV-BEGIN> 8.60
<PER-SHARE-NII> 0.30
<PER-SHARE-GAIN-APPREC> 0.30
<PER-SHARE-DIVIDEND> (0.30)
<PER-SHARE-DISTRIBUTIONS> (0.03)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.87
<EXPENSE-RATIO> 0.92
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
THE FINANCIAL STATEMENTS OF MASSACHUSETTS FINANCIAL SERVICES AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
<NUMBER>022
<NAME> MFS MUNICIPAL HIGH INCOME FUND-CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-1995
<PERIOD-END> JUL-31-1995
<INVESTMENTS-AT-COST> 1,004,843,021
<INVESTMENTS-AT-VALUE> 1,032,625,013
<RECEIVABLES> 26,323,995
<ASSETS-OTHER> 13,101
<OTHER-ITEMS-ASSETS> 41,410
<TOTAL-ASSETS> 1,059,003,519
<PAYABLE-FOR-SECURITIES> 355,042
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 5,779,242
<TOTAL-LIABILITIES> 6,134,284
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,119,640,034
<SHARES-COMMON-STOCK> 7,784,574
<SHARES-COMMON-PRIOR> 6,476,558
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> (1,431,578)
<ACCUMULATED-NET-GAINS> (93,121,213)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 27,781,992
<NET-ASSETS> 1,052,869,235
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 40,208,973
<OTHER-INCOME> 0
<EXPENSES-NET> 5,062,509
<NET-INVESTMENT-INCOME> 35,146,464
<REALIZED-GAINS-CURRENT> (14,333,711)
<APPREC-INCREASE-CURRENT> 48,347,919
<NET-CHANGE-FROM-OPS> 69,160,672
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (2,004,676)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1,570,467
<NUMBER-OF-SHARES-REDEEMED> (357,385)
<SHARES-REINVESTED> 97,934
<NET-CHANGE-IN-ASSETS> 77,151,388
<ACCUMULATED-NII-PRIOR> 1,098,869
<ACCUMULATED-GAINS-PRIOR> (79,164,299)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3,342,223
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5,062,509
<AVERAGE-NET-ASSETS> 64,248,573
<PER-SHARE-NAV-BEGIN> 8.60
<PER-SHARE-NII> 0.26
<PER-SHARE-GAIN-APPREC> 0.29
<PER-SHARE-DIVIDEND> (0.26)
<PER-SHARE-DISTRIBUTIONS> (0.02)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.87
<EXPENSE-RATIO> 1.96
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
