PAGE 1
000 A000000 01/31/2017
000 C000000 0001244183
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 PIMCO INCOME STRATEGY FUND
001 B000000 811-21374
001 C000000 8443374626
002 A000000 1633 BROADWAY
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10019
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
008 A000001 PACIFIC INVESTMENT MANAGEMENT COMPANY LLC
008 B000001 A
008 C000001 801-48187
008 D010001 NEWPORT BEACH
008 D020001 CA
008 D030001 92660
010 A000001 PACIFIC INVESTMENT MANAGEMENT COMPANY LLC
010 B000001 801-48187
010 C010001 NEWPORT BEACH
010 C020001 CA
010 C030001 92660
012 A000001 AMERICAN STOCK TRANSFER & TRUST COMPANY LLC
012 B000001 84-00416
012 C010001 BROOKLYN
012 C020001 NY
012 C030001 11219
013 A000001 PRICEWATERHOUSECOOPERS, LLP
013 B010001 KANSAS CITY
013 B020001 MO
013 B030001 64106
014 A000001 PIMCO INVESTMENTS LLC
014 B000001 8-68686
015 A000001 STATE STREET BANK & TRUST COMPANY
015 B000001 C
015 C010001 KANSAS CITY
015 C020001 MO
015 C030001 64105
015 E010001 X
PAGE 2
015 A000002 BANCO NACIONAL DE MEXICO S.A.
015 B000002 S
015 C010002 MEXICO CITY
015 D010002 MEXICO
015 E040002 X
015 A000003 CITIBANK, N.A.
015 B000003 S
015 C010003 SAO PAULO
015 D010003 BRAZIL
015 E040003 X
015 A000004 CLEARSTREAM BANKING S.A.
015 B000004 S
015 C010004 LUXEMBOURG
015 D010004 LUXEMBOURG
015 E040004 X
015 A000005 DEUTSCHE BANK AG
015 B000005 S
015 C010005 PARIS
015 D010005 FRANCE
015 E040005 X
015 A000006 DEUTSCHE BANK S.P.A.
015 B000006 C
015 C010006 MILAN
015 D010006 ITALY
015 E040006 X
015 A000007 STATE STREET BANK & TRUST CO., UNITED KINGDOM
015 B000007 S
015 C010007 LONDON
015 D010007 UNITED KINGDOM
015 E040007 X
015 A000008 THE HONGKONG & SHANGHAI BANKING CORP., LTD.
015 B000008 S
015 C010008 TOKYO
015 D010008 JAPAN
015 E040008 X
018 000000 Y
019 A000000 Y
019 B000000 178
019 C000000 PIMCOFUNDS
021 000000 0
022 A000001 STATE STREET BANK & TRUST CO.
022 B000001 04-1867445
022 C000001 254104
022 D000001 10152
022 A000002 JPMORGAN CHASE & CO.
022 B000002 13-2624428
022 C000002 90996
022 D000002 42876
022 A000003 DEUTSCHE BANK SECURITIES, INC.
022 B000003 13-2730828
022 C000003 110622
PAGE 3
022 D000003 6338
022 A000004 CITIGROUP GLOBAL MARKETS, INC.
022 B000004 11-2418191
022 C000004 57157
022 D000004 4548
022 A000005 UBS SECURITIES LLC
022 B000005 13-3873456
022 C000005 8463
022 D000005 41575
022 A000006 BANC OF AMERICA SECURITIES LLC
022 B000006 56-2058405
022 C000006 28776
022 D000006 7079
022 A000007 GOLDMAN SACHS & CO.
022 B000007 13-5108880
022 C000007 16829
022 D000007 15207
022 A000008 BARCLAYS, INC.
022 B000008 06-1031656
022 C000008 13804
022 D000008 12992
022 A000009 RBC CAPITAL MARKETS, LLC
022 B000009 41-1416330
022 C000009 1367
022 D000009 23147
022 A000010 CREDIT SUISSE (USA), INC.
022 B000010 13-1898818
022 C000010 6863
022 D000010 4084
023 C000000 621000
023 D000000 192639
024 000000 Y
025 A000001 JPMORGAN CHASE & CO.
025 B000001 13-2624428
025 C000001 D
025 D000001 18893
025 A000002 BANC OF AMERICA SECURITIES LLC
025 B000002 56-2058405
025 C000002 D
025 D000002 17879
025 A000003 GOLDMAN SACHS & CO.
025 B000003 13-5108880
025 C000003 D
025 D000003 14491
025 A000004 BARCLAYS, INC.
025 B000004 06-1031656
025 C000004 D
025 D000004 5948
025 A000005 DEUTSCHE BANK SECURITIES, INC.
025 B000005 13-2730828
025 C000005 D
PAGE 4
025 D000005 5232
025 A000006 CREDIT SUISSE (USA), INC.
025 B000006 13-1898818
025 C000006 D
025 D000006 5173
025 A000007 CITIGROUP GLOBAL MARKETS, INC.
025 B000007 11-2418191
025 C000007 D
025 D000007 4204
025 A000008 STATE STREET BANK & TRUST CO.
025 B000008 04-1867445
025 C000008 D
025 D000008 1481
025 A000009 UBS SECURITIES LLC
025 B000009 13-3873456
025 C000009 D
025 D000009 943
026 A000000 N
026 B000000 N
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 N
028 A010000 0
028 A020000 0
028 A030000 0
028 A040000 0
028 B010000 0
028 B020000 0
028 B030000 0
028 B040000 0
028 C010000 0
028 C020000 0
028 C030000 0
028 C040000 0
028 D010000 0
028 D020000 0
028 D030000 0
028 D040000 0
028 E010000 0
028 E020000 0
028 E030000 0
028 E040000 0
028 F010000 0
028 F020000 0
028 F030000 0
028 F040000 0
PAGE 5
028 G010000 0
028 G020000 0
028 G030000 0
028 G040000 0
028 H000000 0
030 A000000 0
030 B000000 0.00
030 C000000 0.00
031 A000000 0
031 B000000 0
032 000000 0
033 000000 0
035 000000 0
036 B000000 0
038 000000 0
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 0
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 0
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.860
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
PAGE 6
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 N
054 A000000 Y
054 B000000 Y
054 C000000 Y
054 D000000 Y
054 E000000 Y
054 F000000 Y
054 G000000 Y
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 Y
054 L000000 Y
054 M000000 Y
054 N000000 Y
054 O000000 Y
055 A000000 Y
055 B000000 N
056 000000 Y
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
060 B000000 Y
061 000000 0
062 A000000 Y
062 B000000 1.0
062 C000000 3.3
062 D000000 0.9
062 E000000 0.0
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 2.0
062 O000000 5.1
062 P000000 68.3
062 Q000000 48.3
062 R000000 1.1
063 A000000 0
063 B000000 8.9
064 A000000 N
064 B000000 N
PAGE 7
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 Y
070 B010000 Y
070 B020000 N
070 C010000 Y
070 C020000 N
070 D010000 Y
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 Y
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 Y
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 Y
070 K020000 N
070 L010000 Y
070 L020000 Y
070 M010000 Y
070 M020000 Y
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 Y
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 95851
071 B000000 73989
071 C000000 334385
071 D000000 22
072 A000000 6
072 B000000 12565
072 C000000 188
072 D000000 0
072 E000000 0
072 F000000 1529
PAGE 8
072 G000000 0
072 H000000 0
072 I000000 0
072 J000000 0
072 K000000 0
072 L000000 0
072 M000000 25
072 N000000 0
072 O000000 0
072 P000000 209
072 Q000000 0
072 R000000 0
072 S000000 0
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 52
072 X000000 1815
072 Y000000 0
072 Z000000 10938
072AA000000 23607
072BB000000 0
072CC010000 0
072CC020000 9148
072DD010000 13668
072DD020000 0
072EE000000 0
073 A010000 0.5400
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 689
074 B000000 2581
074 C000000 11737
074 D000000 343634
074 E000000 2985
074 F000000 86
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 2286
074 K000000 0
074 L000000 3820
074 M000000 6448
074 N000000 374266
074 O000000 4400
074 P000000 247
074 Q000000 0
074 R010000 34842
074 R020000 0
074 R030000 0
PAGE 9
074 R040000 5737
074 S000000 51275
074 T000000 277765
074 U010000 25313
074 U020000 0
074 V010000 10.97
074 V020000 0.00
074 W000000 0.0000
074 X000000 14443
074 Y000000 40649
075 A000000 0
075 B000000 271989
076 000000 10.87
077 A000000 Y
077 B000000 N
077 C000000 N
077 D000000 N
077 E000000 N
077 F000000 N
077 G000000 N
077 H000000 N
077 I000000 N
077 J000000 N
077 K000000 N
077 L000000 N
077 M000000 N
077 N000000 N
077 O000000 N
077 P000000 N
077 Q010000 N
077 Q020000 N
077 Q030000 Y
078 000000 N
080 C000000 0
081 B000000 0
082 B000000 0
083 B000000 0
084 B000000 0
086 A010000 0
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
087 A010000 COMMON
PAGE 10
087 A020000 72201H108
087 A030000 PFL
087 B010000 PREFERRED SERIES T
087 B020000 72201H207
087 C010000 PREFERRED SERIES W
087 C020000 72201H306
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE WILLIAM G. GALIPEAU
TITLE TREASURER