PAGE 1 000 A000000 10/31/2013 000 C000000 0001232860 000 D000000 N 000 E000000 NF 000 F000000 Y 000 G000000 N 000 H000000 N 000 I000000 6.1 000 J000000 A 001 A000000 BLK MUNI INTERMEDIATE DURATION FUND, INC. 001 B000000 811-21348 001 C000000 8004417762 002 A000000 100 BELLEVUE PARKWAY 002 B000000 WILMINGTON 002 C000000 DE 002 D010000 19809 003 000000 N 004 000000 N 005 000000 N 006 000000 N 007 A000000 N 007 B000000 0 007 C010100 1 008 A000001 BLACKROCK ADVISORS, LLC 008 B000001 A 008 C000001 801-47710 008 D010001 WILMINGTON 008 D020001 DE 008 D030001 19809 008 A000002 BLACKROCK INVESTMENT MANAGEMENT, LLC 008 B000002 S 008 C000002 801-56972 008 D010002 PRINCETON 008 D020002 NJ 008 D030002 08540 012 A000001 COMPUTERSHARE TRUST COMPANY, N.A. 012 B000001 85-11340 012 C010001 CANTON 012 C020001 MA 012 C030001 02021 012 A000002 THE BANK OF NEW YORK MELLON (PREFERRED) 012 B000002 85-05006 012 C010002 NEW YORK 012 C020002 NY 012 C030002 10289 013 A000001 DELOITTE & TOUCHE LLP 013 B010001 BOSTON 013 B020001 MA 013 B030001 02116 014 A000001 BLACKROCK CAPITAL MARKETS, LLC 014 B000001 8-67827 PAGE 2 014 A000002 BLACKROCK EXECUTION SERVICES 014 B000002 8-48719 014 A000003 BLACKROCK INVESTMENTS, LLC 014 B000003 8-48436 014 A000004 HARRIS WILLIAMS LLC 014 B000004 8-53380 014 A000005 PNC CAPITAL MARKETS, INC. 014 B000005 8-32493 014 A000006 PNC INVESTMENTS LLC 014 B000006 8-66195 015 A000001 STATE STREET BANK & TRUST COMPANY 015 B000001 C 015 C010001 BOSTON 015 C020001 MA 015 C030001 02110 015 E010001 X 015 A000002 THE BANK OF NEW YORK MELLON 015 B000002 S 015 C010002 NEW YORK 015 C020002 NY 015 C030002 10286 015 E010002 X 015 A000003 J.P. MORGAN CHASE BANK 015 B000003 S 015 C010003 NEW YORK 015 C020003 NY 015 C030003 10017 015 E010003 X 018 000000 Y 019 A000000 Y 019 B000000 283 019 C000000 BLKRKADVSR 020 A000001 BANK OF AMERICA SECURITIES LLC. 020 B000001 56-2058405 020 C000001 2 021 000000 2 022 A000001 FFI INSTITUTIONAL TAX-EXEMPT FUND 022 B000001 22-2509978 022 C000001 129832 022 D000001 115690 022 A000002 CITIGROUP GLOBAL MARKETS INC. 022 B000002 11-2418191 022 C000002 21576 022 D000002 19175 022 A000003 J.P. MORGAN SECURITIES INC. 022 B000003 13-3299429 022 C000003 25808 022 D000003 8902 022 A000004 BANK OF AMERICA SECURITIES LLC. 022 B000004 56-2058405 022 C000004 18071 PAGE 3 022 D000004 5655 022 A000005 PERSHING LLC 022 B000005 13-2741729 022 C000005 5301 022 D000005 17172 022 A000006 MORGAN STANLEY 022 B000006 36-3145972 022 C000006 0 022 D000006 21459 022 A000007 RAYMOND JAMES FINANCIAL INC 022 B000007 59-1517485 022 C000007 11220 022 D000007 1041 022 A000008 STIFEL NICOLAUS & COMPANY INCORPORATED 022 B000008 43-0538770 022 C000008 2672 022 D000008 7462 022 A000009 PIPER JAFFRAY & CO 022 B000009 41-0953246 022 C000009 2119 022 D000009 7485 022 A000010 NATIONAL FINANCIAL SERVICES LLC 022 B000010 04-3523567 022 C000010 7639 022 D000010 1286 023 C000000 242831 023 D000000 231080 024 000000 N 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 PAGE 4 028 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 0 028 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 0.550 048 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 PAGE 5 048 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 0.000 049 000000 N 050 000000 N 051 000000 N 052 000000 N 053 A000000 Y 053 B000000 Y 053 C000000 N 054 A000000 Y 054 B000000 Y 054 C000000 N 054 D000000 N 054 E000000 N 054 F000000 N 054 G000000 N 054 H000000 Y 054 I000000 N 054 J000000 Y 054 K000000 N 054 L000000 N 054 M000000 Y 054 N000000 N 055 A000000 N 055 B000000 N 056 000000 Y 057 000000 N 058 A000000 N 059 000000 Y 060 A000000 N 060 B000000 N 061 000000 0 062 A000000 Y 062 B000000 0.0 062 C000000 0.0 062 D000000 0.0 062 E000000 0.0 062 F000000 0.0 062 G000000 0.0 062 H000000 0.0 062 I000000 0.0 062 J000000 0.0 PAGE 6 062 K000000 0.0 062 L000000 3.4 062 M000000 0.0 062 N000000 0.0 062 O000000 160.8 062 P000000 0.0 062 Q000000 0.0 062 R000000 0.0 063 A000000 0 063 B000000 13.6 064 A000000 Y 064 B000000 N 066 A000000 N 067 000000 N 068 A000000 N 068 B000000 N 069 000000 N 070 A010000 Y 070 A020000 N 070 B010000 N 070 B020000 N 070 C010000 Y 070 C020000 N 070 D010000 N 070 D020000 N 070 E010000 Y 070 E020000 Y 070 F010000 N 070 F020000 N 070 G010000 Y 070 G020000 N 070 H010000 N 070 H020000 N 070 I010000 N 070 I020000 N 070 J010000 N 070 J020000 N 070 K010000 Y 070 K020000 Y 070 L010000 N 070 L020000 N 070 M010000 N 070 M020000 N 070 N010000 Y 070 N020000 N 070 O010000 Y 070 O020000 N 070 P010000 Y 070 P020000 N 070 Q010000 N 070 Q020000 N PAGE 7 070 R010000 Y 070 R020000 N 071 A000000 112999 071 B000000 144830 071 C000000 958449 071 D000000 12 072 A000000 6 072 B000000 20567 072 C000000 0 072 D000000 0 072 E000000 2 072 F000000 2683 072 G000000 62 072 H000000 0 072 I000000 26 072 J000000 23 072 K000000 0 072 L000000 7 072 M000000 47 072 N000000 1 072 O000000 0 072 P000000 1930 072 Q000000 0 072 R000000 30 072 S000000 31 072 T000000 0 072 U000000 0 072 V000000 0 072 W000000 53 072 X000000 4893 072 Y000000 2 072 Z000000 15678 072AA000000 0 072BB000000 2970 072CC010000 0 072CC020000 53339 072DD010000 16429 072DD020000 0 072EE000000 0 073 A010000 0.4290 073 A020000 0.0000 073 B000000 0.0000 073 C000000 0.0000 074 A000000 679 074 B000000 0 074 C000000 1700 074 D000000 930618 074 E000000 0 074 F000000 0 074 G000000 0 074 H000000 0 PAGE 8 074 I000000 17810 074 J000000 1981 074 K000000 0 074 L000000 12924 074 M000000 178 074 N000000 965890 074 O000000 13539 074 P000000 441 074 Q000000 0 074 R010000 0 074 R020000 0 074 R030000 0 074 R040000 86218 074 S000000 287100 074 T000000 578592 074 U010000 38296 074 U020000 0 074 V010000 15.11 074 V020000 0.00 074 W000000 0.0000 074 X000000 21635 074 Y000000 330569 075 A000000 0 075 B000000 870157 076 000000 13.91 077 A000000 Y 077 O000000 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 STOCK 087 A020000 09253X102 087 A030000 MUI 087 B010000 PREFERRED SHARES 088 A000000 Y 088 B000000 N PAGE 9 088 C000000 N 088 D000000 Y SIGNATURE NEAL J. ANDREWS TITLE CFO