<PAGE> PAGE 1
000 B000000 10/31/98
000 C000000 0000356013
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 MERRILL LYNCH RETIREMENT SERIES TRUST
001 B000000 811-3310
001 C000000 6092822800
002 A000000 P.O. BOX 9011
002 B000000 PRINCETON
002 C000000 NJ
002 D010000 08543
002 D020000 9011
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 1
007 C010100 1
007 C020100 MERRILL LYNCH RETIREMENT RESERVES MONEY FUND
007 C030100 N
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
020 C000001 0
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 0
022 A000001 HSBC SECURITIES, INC.
022 B000001 13-2650272
022 C000001 57200341
022 D000001 1603005
022 A000002 FUJI SECURITIES INC.
<PAGE> PAGE 2
022 B000002 36-2880742
022 C000002 17364718
022 D000002 84223
022 A000003 GOLDMAN, SACHS & CO.
022 B000003 13-5108880
022 C000003 13596677
022 D000003 483952
022 A000004 LEHMAN BROTHERS COMMERCIAL PAPER
022 C000004 10799561
022 D000004 845743
022 A000005 NOMURA SECURITIES INTERNATIONAL, INC.
022 B000005 13-2642206
022 C000005 8106415
022 D000005 14986
022 A000006 LEHMAN BROTHERS INC.
022 B000006 13-2518466
022 C000006 6332816
022 D000006 69102
022 A000007 CREDIT SUISSE FIRST BOSTON CORPORATION
022 B000007 13-5659485
022 C000007 5818429
022 D000007 424619
022 A000008 MORGAN (J.P.) SECURITIES INC.
022 B000008 13-3224016
022 C000008 3874101
022 D000008 285409
022 A000009 CHASE SECURITIES INC.
022 B000009 13-3112953
022 C000009 3567525
022 D000009 74812
022 A000010 MORGAN STANLEY & CO. INCORPORATED
022 B000010 13-2655998
022 C000010 2367487
022 D000010 238554
023 C000000 151117735
023 D000000 5262294
026 A000000 N
026 B000000 Y
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
077 A000000 Y
077 B000000 Y
077 P000000 Y
078 000000 N
008 A000101 MERRILL LYNCH ASSET MANAGEMENT, L.P.
<PAGE> PAGE 3
008 B000101 A
008 C000101 801-11583
008 D010101 PRINCETON
008 D020101 NJ
008 D030101 08543
008 D040101 9011
011 A000101 MERRILL LYNCH FUNDS DISTRIBUTOR, INC.
011 B000101 8-14663
011 C010101 PRINCETON
011 C020101 NJ
011 C030101 08543
011 C040101 9011
012 A000101 FINANCIAL DATA SERVICES, INC.
012 B000101 84-01339
012 C010101 JACKSONVILLE
012 C020101 FL
012 C030101 32246
012 C040101 6484
013 A000101 DELOITTE & TOUCHE LLP
013 B010101 PRINCETON
013 B020101 NJ
013 B030101 08540
014 A000101 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
014 B000101 8-7221
015 A000101 THE BANK OF NEW YORK
015 B000101 C
015 C010101 NEW YORK
015 C020101 NY
015 C030101 10286
015 E010101 X
015 A000102 BANKERS TRUST COMPANY
015 B000102 S
015 C010102 NEW YORK
015 C020102 NY
015 C030102 10006
015 E010102 X
015 A000103 CHASE MANAHTTAN BANK, N.A.
015 B000103 S
015 C010103 NEW YORK
015 C020103 NY
015 C030103 10017
015 E010103 X
015 A000104 CUSTODIAL TRUST CO.
015 B000104 S
015 C010104 NEW YORK
015 C020104 NY
015 C030104 10167
015 E010104 X
015 A000105 MORGAN GUARANTEE TRUST CO.
015 B000105 S
015 C010105 NEW YORK
<PAGE> PAGE 4
015 C020105 NY
015 C030105 10260
015 E010105 X
018 000100 Y
019 A000100 Y
019 B000100 212
019 C000100 MERRILLLYN
024 000100 Y
025 A000101 GOLDMAN SACHS GROUP, L.P.
025 C000101 D
025 D000101 308961
025 A000102 LEHMAN BROTHERS HOLDINGS INC.
025 C000102 D
025 D000102 197854
025 A000103 MORGAN STANLEY, DEAN WITTER & CO.
025 C000103 D
025 D000103 82900
025 A000104 DELETE
025 D000104 0
025 D000105 0
025 D000106 0
025 D000107 0
025 D000108 0
028 A010100 3255969
028 A020100 47294
028 A030100 0
028 A040100 3143688
028 B010100 3368639
028 B020100 54393
028 B030100 0
028 B040100 3601016
028 C010100 3609877
028 C020100 52494
028 C030100 0
028 C040100 3312952
028 D010100 3863115
028 D020100 51078
028 D030100 0
028 D040100 3290462
028 E010100 3758257
028 E020100 59444
028 E030100 0
028 E040100 3307206
028 F010100 4098945
028 F020100 58042
028 F030100 0
028 F040100 3475952
028 G010100 21954802
028 G020100 322745
028 G030100 0
028 G040100 20131276
<PAGE> PAGE 5
028 H000100 0
029 000100 N
030 A000100 0
030 B000100 0.00
030 C000100 0.00
034 000100 N
035 000100 0
036 B000100 0
037 000100 N
038 000100 0
039 000100 N
040 000100 Y
041 000100 Y
042 A000100 0
042 B000100 0
042 C000100 100
042 D000100 0
042 E000100 0
042 F000100 0
042 G000100 0
042 H000100 0
043 000100 3
044 000100 0
045 000100 Y
046 000100 N
047 000100 Y
048 000100 0.000
048 A010100 1000000
048 A020100 0.500
048 B010100 1000000
048 B020100 0.450
048 C010100 1000000
048 C020100 0.400
048 D010100 1000000
048 D020100 0.375
048 E010100 3000000
048 E020100 0.350
048 F010100 3000000
048 F020100 0.325
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 10000000
048 K020100 0.300
049 000100 N
050 000100 N
<PAGE> PAGE 6
051 000100 N
052 000100 N
053 A000100 N
054 A000100 Y
054 B000100 Y
054 C000100 N
054 D000100 N
054 E000100 N
054 F000100 N
054 G000100 N
054 H000100 Y
054 I000100 N
054 J000100 Y
054 K000100 N
054 L000100 N
054 M000100 Y
054 N000100 N
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 1
062 A000100 Y
062 B000100 1.9
062 C000100 23.0
062 D000100 0.0
062 E000100 0.0
062 F000100 8.3
062 G000100 1.5
062 H000100 0.0
062 I000100 43.6
062 J000100 0.0
062 K000100 0.0
062 L000100 22.4
062 M000100 0.0
062 N000100 0.0
062 O000100 0.0
062 P000100 0.0
062 Q000100 0.0
062 R000100 0.0
063 A000100 73
063 B000100 0.0
064 A000100 N
066 A000100 N
067 000100 N
068 A000100 N
068 B000100 N
<PAGE> PAGE 7
069 000100 N
070 A010100 Y
070 A020100 Y
070 B010100 N
070 B020100 N
070 C010100 N
070 C020100 N
070 D010100 N
070 D020100 N
070 E010100 N
070 E020100 N
070 F010100 N
070 F020100 N
070 G010100 N
070 G020100 N
070 H010100 N
070 H020100 N
070 I010100 N
070 I020100 N
070 J010100 Y
070 J020100 Y
070 K010100 N
070 K020100 N
070 L010100 Y
070 L020100 Y
070 M010100 N
070 M020100 N
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 0
071 B000100 0
071 C000100 0
071 D000100 0
072 A000100 12
072 B000100 680667
072 C000100 0
072 D000100 0
072 E000100 0
072 F000100 43136
072 G000100 500
072 H000100 0
072 I000100 16158
072 J000100 338
<PAGE> PAGE 8
072 K000100 0
072 L000100 853
072 M000100 79
072 N000100 1371
072 O000100 0
072 P000100 10
072 Q000100 0
072 R000100 36
072 S000100 84
072 T000100 3
072 U000100 0
072 V000100 0
072 W000100 2682
072 X000100 65250
072 Y000100 0
072 Z000100 615417
072AA000100 1967
072BB000100 675
072CC010100 3921
072CC020100 0
072DD010100 615417
072DD020100 0
072EE000100 1292
073 A010100 0.0517
073 A020100 0.0000
073 B000100 0.0001
073 C000100 0.0000
074 A000100 49
074 B000100 0
074 C000100 14075489
074 D000100 0
074 E000100 0
074 F000100 0
074 G000100 0
074 H000100 0
074 I000100 0
074 J000100 176717
074 K000100 0
074 L000100 62993
074 M000100 582
074 N000100 14315830
074 O000100 182344
074 P000100 4015
074 Q000100 0
074 R010100 0
074 R020100 0
074 R030100 0
074 R040100 155365
074 S000100 0
074 T000100 13974106
074 U010100 13917721
<PAGE> PAGE 9
074 U020100 56385
074 V010100 1.00
074 V020100 1.00
074 W000100 0.0000
074 X000100 2272698
074 Y000100 0
075 A000100 11932223
075 B000100 0
076 000100 0.00
080 A000100 ICI MUTUAL INSURANCE CO.
080 C000100 2500
081 A000100 Y
081 B000100 133
082 A000100 N
082 B000100 0
083 A000100 N
083 B000100 0
084 A000100 N
084 B000100 0
085 A000100 Y
085 B000100 N
SIGNATURE GERALD M. RICHARD
TITLE TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000356013
<NAME> MERRILL LYNCH RETIREMENT SERIES TRUST
<SERIES>
<NUMBER> 011
<NAME> MERRILL LYNCH RETIREMENT RESERVES MONEY FUND
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> OCT-31-1998
<PERIOD-START> NOV-01-1997
<PERIOD-END> OCT-31-1998
<INVESTMENTS-AT-COST> 14071100127
<INVESTMENTS-AT-VALUE> 14075488619
<RECEIVABLES> 239710304
<ASSETS-OTHER> 630848
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 14315829771
<PAYABLE-FOR-SECURITIES> 182343558
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 159379950
<TOTAL-LIABILITIES> 341723508
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 13969717771
<SHARES-COMMON-STOCK> 13913317927
<SHARES-COMMON-PRIOR> 10689877146
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 4388492
<NET-ASSETS> 13917721375
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 680666770
<OTHER-INCOME> 0
<EXPENSES-NET> (65249600)
<NET-INVESTMENT-INCOME> 615417170
<REALIZED-GAINS-CURRENT> 1292223
<APPREC-INCREASE-CURRENT> 3920495
<NET-CHANGE-FROM-OPS> 620629888
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (615358911)
<DISTRIBUTIONS-OF-GAINS> (1292074)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 42739661096
<NUMBER-OF-SHARES-REDEEMED> (40132831388)
<SHARES-REINVESTED> 616611073
<NET-CHANGE-IN-ASSETS> 3283761121
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 43135917
<INTEREST-EXPENSE> 9669
<GROSS-EXPENSE> 65249600
<AVERAGE-NET-ASSETS> 11915974313
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> .05
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (.05)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .55
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000356013
<NAME> MERRILL LYNCH RETIREMENT SERIES TRUST
<SERIES>
<NUMBER> 012
<NAME> MERRILL LYNCH RETIREMENT RESERVES MONEY FUND
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> OCT-31-1998
<PERIOD-START> NOV-01-1997
<PERIOD-END> OCT-31-1998
<INVESTMENTS-AT-COST> 14071100127
<INVESTMENTS-AT-VALUE> 14075488619
<RECEIVABLES> 239710304
<ASSETS-OTHER> 630848
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 14315829771
<PAYABLE-FOR-SECURITIES> 182343558
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 159379950
<TOTAL-LIABILITIES> 341723508
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 13969717771
<SHARES-COMMON-STOCK> 56399845
<SHARES-COMMON-PRIOR> 0
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 4388492
<NET-ASSETS> 56384888
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 680666770
<OTHER-INCOME> 0
<EXPENSES-NET> (65249600)
<NET-INVESTMENT-INCOME> 615417170
<REALIZED-GAINS-CURRENT> 1292223
<APPREC-INCREASE-CURRENT> 3920495
<NET-CHANGE-FROM-OPS> 620629888
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (58259)
<DISTRIBUTIONS-OF-GAINS> (149)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 85369645
<NUMBER-OF-SHARES-REDEEMED> (29028235)
<SHARES-REINVESTED> 58435
<NET-CHANGE-IN-ASSETS> 3283761121
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 43135917
<INTEREST-EXPENSE> 9669
<GROSS-EXPENSE> 65249600
<AVERAGE-NET-ASSETS> 16248439
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .72
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
