BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED

MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number: 811-21348

Name of Fund: BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

Fund Address: 100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: John M. Perlowski, Chief Executive Officer, BlackRock Muni

Intermediate Duration Fund, Inc., 55 East 52nd Street, New York, NY 10055

Registrant’s telephone number, including area code: (800) 882-0052, Option 4

Date of fiscal year end: 04/30/2016

Date of reporting period: 07/31/2015

Item 1 – Schedule of Investments

Schedule of Investments July 31, 2015 (Unaudited)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

Alabama — 2.9%

     

City of Birmingham Alabama Special Care Facilities Financing Authority, RB, Children’s Hospital (AGC), 6.00%, 6/01/34

    $ 4,615      $ 5,287,267   

County of Jefferson Alabama, RB, Limited Obligation School, Series A:

     

5.50%, 1/01/21

      5,500        5,541,250   

5.25%, 1/01/23

      6,500        6,548,750   
    

 

 

  
        17,377,267   

Arizona — 4.1%

     

Arizona Board of Regents, Univesity of Arizona, RB, 5.00%, 8/01/28

      2,000        2,280,460   

Arizona Health Facilities Authority, Refunding RB, Phoenix Children’s Hospital, Series A, 5.00%, 2/01/30

      2,685        2,865,835   

City of Phoenix Arizona IDA, RB, Facility, Legacy Traditional Schools Project, Series A, 5.75%, 7/01/24 (a)

      750        805,658   

City of Tucson Arizona, COP, Refunding (AGC), 4.00%, 7/01/20

      2,325        2,578,541   

County of Maricopa Arizona IDA, RB, Arizona Charter School Project 1, Series A, 6.63%, 7/01/20

      110        107,500   

County of Pima Arizona IDA, RB, Arizona Charter Schools Project, Series K, 6.38%, 7/01/31

      895        901,390   

County of Pinal Arizona Electric District No. 3, Refunding RB, 5.00%, 7/01/25

      1,600        1,791,616   

Glendale Union School District No. 205, GO, Series C:

     

5.00%, 7/01/24

      1,945        2,294,555   

5.00%, 7/01/27

      500        573,220   

Phoenix-Mesa Gateway Airport Authority, RB, Mesa Project, AMT:

     

5.00%, 7/01/27

      700        786,156   

5.00%, 7/01/32

      1,925        2,102,196   

Salt River Project Agricultural Improvement & Power District, RB, Series A, 5.00%, 1/01/25

      4,000        4,388,120   

Scottsdale IDA, Refunding RB, Scottsdale Healthcare, Series C (AGM), 5.00%, 9/01/35

      2,050        2,252,069   
Municipal Bonds   

Par  

(000)

     Value  

Arizona (concluded)

     

State of Arizona, COP, Department of Administration, Series A (AGM), 4.25%, 10/01/23

    $ 1,000      $ 1,073,530   
    

 

 

  
        24,800,846   

Arkansas — 1.1%

     

Arkansas State University, RB, 5.00%, 12/01/33

      480        541,992   

City of Benton, RB:

     

5.00%, 6/01/28

      600        688,434   

5.00%, 6/01/29

      1,055        1,204,430   

University of Arkansas, Refunding RB:

     

5.00%, 3/01/31

      2,315        2,683,455   

5.00%, 3/01/34

      1,270        1,456,233   
    

 

 

  
        6,574,544   

California — 3.5%

     

California Health Facilities Financing Authority, RB, Sutter Health, Series B, 5.00%, 8/15/22

      2,135        2,476,429   

California Pollution Control Financing Authority, RB, Mandatory Put Bonds, Republic Services, Inc. Project, Series B, AMT, 5.25%, 6/01/23 (b)

      605        648,016   

California Pollution Control Financing Authority, Refunding RB, Pacific Gas, Series C, AMT (NPFGC), 4.75%, 12/01/23

      5,000        5,258,000   

City of San Jose California, Refunding ARB, Series A-1, AMT, 5.00%, 3/01/25

      2,000        2,218,700   

State of California, GO:

     

5.50%, 4/01/28

      15        15,066   

5.00%, 11/01/32

      2,000        2,166,780   

Various Purposes, 5.75%, 4/01/31

      7,000        8,122,590   
    

 

 

  
        20,905,581   

Colorado — 0.9%

     

Denver Urban Renewal Authority, Refunding, Tax Allocation Bond, Stapleton, Senior-Series A-1, 5.00%, 12/01/23

      2,500        2,898,000   

 

                
   BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015    1

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

Colorado (concluded)

     

University of Northern Colorado, Refunding RB, Series A, 5.00%, 6/01/31

    $ 2,000      $ 2,306,620   
    

 

 

  
        5,204,620   

Connecticut — 2.3%

     

Connecticut State Development Authority, RB, Learjet, Inc. Project, AMT, 7.95%, 4/01/26

      1,160        1,171,647   

Connecticut State Health & Educational Facility Authority, Refunding RB, Lawrence & Memorial Hospital, Series F, 5.00%, 7/01/31

      4,530        4,915,367   

State of Connecticut, GO, Series B, 5.00%, 4/15/31

      6,990        7,887,446   
    

 

 

  
        13,974,460   

Florida — 5.9%

     

County of Broward Florida School Board, COP, Refunding, Series A (AGM), 5.00%, 7/01/24

      10,000        11,331,600   

County of Highlands Florida Health Facilities Authority, Refunding RB, Adventis Health, Series G, 5.13%, 11/15/16 (c)

      35        37,076   

County of Lee Florida, Refunding ARB, Series A, AMT:

     

5.50%, 10/01/23

      1,000        1,171,000   

(AGM), 5.00%, 10/01/27

      1,635        1,845,473   

County of Miami-Dade Florida, RB, AMT, Series B:

     

6.00%, 10/01/28

      3,470        4,214,697   

6.00%, 10/01/29

      3,480        4,225,451   

County of Miami-Dade Florida Transit System Sales Surtax Revenue, Refunding RB, 5.00%, 7/01/32

      1,500        1,679,130   

County of Miami-Dade Florida Water & Sewer System Revenue, Refunding RB, Series C (BHAC), 5.00%, 10/01/18 (c)

      8,000        9,006,880   

Midtown Miami Community Development District, Refunding, Special Assessment Bonds, Series A, 4.25%, 5/01/24

      1,835        1,940,402   
Municipal Bonds   

Par  

(000)

     Value  

Florida (concluded)

     

Sterling Hill Community Development District, Refunding RB, Special Assessment Bonds, Series B, 5.50%, 11/01/10 (d)(e)

    $ 155      $ 93,005   
    

 

 

  
        35,544,714   

Georgia — 3.1%

     

City of Atlanta Georgia Water & Wastewater Revenue RB, Refunding RB, 5.00%, 11/01/32

      10,000        11,542,200   

Fulton County Development Authority, Refunding RB, Robert Woodruff, Series B, 5.25%, 3/15/24

      3,000        3,320,460   

Medical Center Hospital Authority, Refunding RB, Columbus Regional Healthcare (AGM):

     

4.00%, 8/01/23

      1,500        1,578,255   

4.13%, 8/01/24

      2,000        2,103,120   
    

 

 

  
        18,544,035   

Guam — 0.4%

     

Territory of Guam, RB, Section 30, Series A, 5.38%, 12/01/24

      2,100        2,323,419   

Hawaii — 0.9%

     

State of Hawaii Airports System, Refunding ARB, Series A, 5.25%, 7/01/29

      5,000        5,715,700   

Illinois — 16.0%

     

City of Chicago Illinois Midway International Airport, Refunding ARB, 2nd Lien, Series A, AMT, 5.50%, 1/01/32

      1,500        1,665,465   

City of Chicago Illinois Midway International Airport, Refunding RB, AMT, Series A, 5.00%, 1/01/32

      5,000        5,372,650   

City of Chicago Illinois O’Hare International Airport, Refunding GARB, AMT:

     

Series C, 5.25%, 1/01/28

      1,350        1,484,595   

Series C, 5.25%, 1/01/29

      3,020        3,298,565   

Senior Lien, Series A, 5.00%, 1/01/23

      13,000        14,754,090   

City of Chicago Illinois Transit Authority, RB, 5.25%, 12/01/31

      3,700        3,958,445   

 

                
2    BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015   

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

Illinois (concluded)

     

Madison-Macoupin Etc. Counties Community College District No. 536, GO, Refunding, Lewis & Clark Community College:

     

5.00%, 5/01/30

    $ 475      $ 528,072   

5.00%, 5/01/31

      500        554,880   

5.00%, 5/01/32

      500        557,545   

McHenry County Conservation District, GO, 5.13%, 2/01/17 (c)

      12,695        13,560,672   

Railsplitter Tobacco Settlement Authority, RB:

     

5.50%, 6/01/23

      3,500        4,042,745   

6.25%, 6/01/24

      12,750        13,357,155   

State of Illinois, GO:

     

5.25%, 2/01/30

      5,000        5,237,250   

5.00%, 5/01/30

      10,000        10,306,600   

State of Illinois Toll Highway Authority, RB, Series A, 5.00%, 1/01/34

      9,140        10,097,598   

Village of Hodgkins Illinois, RB, MBM Project, AMT, 5.90%, 11/01/17

      6,000        6,009,840   

Village of Wheeling Illinois, Tax Allocation Bonds, North Milwaukee/Lake-Cook TIF Project, 6.00%, 1/01/25

      1,290        1,290,425   
    

 

 

  
        96,076,592   

Indiana — 4.1%

     

City of Whiting Indiana, RB, BP Products North America, Inc. Project, 5.25%, 1/01/21

      4,800        5,562,240   

County of Jasper Indiana, Refunding RB, Northern Indiana Public Service Co., Series C (NPFGC), 5.85%, 4/01/19

      2,000        2,266,480   

Indiana Finance Authority, RB, Wastewater, 1st Lien, Series A, 5.25%, 10/01/31

      10,000        11,554,900   

Indiana Finance Authority, Refunding RB, US Steel Corp. Project, 6.00%, 12/01/19

      5,000        5,544,950   
    

 

 

  
        24,928,570   

Iowa — 1.0%

     

Iowa Higher Education Loan Authority, RB, Private College Facility:

     

5.25%, 4/01/23

      695        789,680   

5.25%, 4/01/24

      730        837,821   

5.25%, 4/01/25

      520        592,015   

5.25%, 4/01/26

      360        406,516   
Municipal Bonds   

Par  

(000)

     Value  

Iowa (concluded)

     

Iowa Higher Education Loan Authority, Refunding RB, Private College Facility:

     

5.00%, 9/01/22

    $ 2,315      $ 2,410,725   

Upper Iowa University Project, 5.00%, 9/01/20

      1,000        1,064,950   
    

 

 

  
        6,101,707   

Kansas — 1.4%

     

Kansas Development Finance Authority, Refunding RB, Adventist Health System/Sunbelt Obligated Group, Series C, 5.00%, 11/15/23

      1,500        1,683,900   

Seward County Unified School District No. 480 Liberal, GO, Refunding, 5.00%, 9/01/33

      6,000        6,663,420   
    

 

 

  
        8,347,320   

Kentucky — 1.5%

     

State of Kentucky Property & Building Commission, Refunding RB, Project No. 93 (AGC), 5.25%, 2/01/24

      8,000        9,027,120   

Louisiana — 6.3%

     

City of Bossier City Louisiana Utilities, Refunding RB, 5.00%, 10/01/32

      2,000        2,277,140   

City of New Orleans Louisiana Aviation Board, Refunding GARB, Restructuring, Series A-2 (AGC), 6.00%, 1/01/23

      850        965,957   

Jefferson Parish Hospital Service District No. 1, Refunding RB, West Jefferson Medical Center, Series A (AGM), 5.50%, 1/01/26

      3,000        3,430,350   

Louisiana Local Government Environmental Facilities & Community Development Authority, Refunding RB:

     

5.00%, 11/01/32

      7,000        7,981,610   

BRCC Facilities Corp. Project, 5.00%, 12/01/27

      3,445        3,853,095   

BRCC Facilities Corp. Project, 5.00%, 12/01/28

      3,715        4,136,913   

Louisiana Public Facilities Authority, Refunding RB, Entergy Gulf States Louisiana LLC Project, Series A, 5.00%, 9/01/28

      2,000        2,007,500   

 

                
   BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015    3

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

Louisiana (concluded)

     

New Orleans Aviation Board, RB, Series A:

     

5.00%, 1/01/31

    $ 855      $ 964,423   

5.00%, 1/01/32

      1,000        1,124,550   

5.00%, 1/01/33

      1,000        1,122,840   

State of Louisiana Gasoline & Fuels Tax Revenue, Refunding RB, 4.00%, 5/01/34

      5,750        5,977,412   

Terrebonne Levee & Conservation District, RB, Sales Tax, 5.00%, 7/01/28

      3,660        4,078,155   
    

 

 

  
        37,919,945   

Maine — 0.3%

     

Portland Housing Development Corp., Refunding RB, Senior Living, Retirement Facilities, Series A, 6.00%, 2/01/34

      1,965        1,977,124   

Maryland — 0.8%

     

Maryland EDC, RB, Transportation Facilities Project, Series A, 5.13%, 6/01/20

      1,750        1,910,738   

Maryland Health & Higher Educational Facilities Authority, RB, Johns Hopkins Health System, Series B, 5.00%, 7/01/33

      1,140        1,264,146   

Maryland Health & Higher Educational Facilities Authority, Refunding RB, 5.00%, 7/01/33

      1,500        1,642,140   
    

 

 

  
        4,817,024   

Massachusetts — 1.5%

     

Massachusetts Development Finance Agency, Refunding RB, 5.00%, 1/01/31

      1,730        1,873,054   

Massachusetts Health & Educational Facilities Authority, Refunding RB, Winchester Hospital, 5.00%, 7/01/25

      1,060        1,174,363   

Massachusetts School Building Authority, RB, Dedicated Sales Tax, Series A (AGM), 5.00%, 8/15/15 (c)

      5,870        5,880,918   
    

 

 

  
        8,928,335   

Michigan — 2.3%

     

Manistee Area Public Schools, GO, Refunding (Q-SBLF), 5.00%, 5/01/25

      1,000        1,124,360   
Municipal Bonds   

Par  

(000)

     Value  

Michigan (concluded)

     

Michigan Finance Authority, Refunding RB, Senior Lien, Detroit Water and Sewer, Series C-3, 5.00%, 7/01/31

    $ 4,000      $ 4,420,560   

Michigan State Building Authority, Refunding RB, Facilities Program, Series II-A, 5.00%, 10/15/24

      2,500        2,864,775   

Michigan State Hospital Finance Authority, Refunding RB, Henry Ford Health System, 5.25%, 11/15/24

      4,900        5,492,949   
    

 

 

  
        13,902,644   

Minnesota — 1.5%

     

City of St. Cloud Minnesota, Refunding RB, Centracare Health System, Series A, 4.25%, 5/01/21

      2,300        2,539,982   

St. Cloud Minnesota Independent School District No. 742, GO, Series A, 3.00%, 2/01/31

      350        338,580   

University of Minnesota, RB, Biomedical Science Research Facilities Funding Program:

     

Series B, 5.00%, 8/01/36

      1,000        1,121,910   

Series C, 5.00%, 8/01/27

      1,390        1,612,233   

Series C, 5.00%, 8/01/28

      740        853,953   

Series C, 5.00%, 8/01/29

      1,555        1,781,874   

Series C, 5.00%, 8/01/30

      835        954,271   
    

 

 

  
        9,202,803   

Mississippi — 0.7%

     

Mississippi Business Finance Corp., Refunding RB, System Energy Resource, Inc. Project, 5.88%, 4/01/22

      4,190        4,214,428   

Missouri — 0.9%

     

Missouri Joint Municipal Electric Utility Commission Power, RB, Prairie State Project, Series A (BHAC), 5.00%, 1/01/17 (c)

      5,000        5,312,050   

Montana — 0.3%

     

Montana State Board of Regents, RB, 5.00%, 11/15/30

      1,000        1,156,090   

 

                
4    BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015   

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

Montana (concluded)

     

Yellowstone County School District No. 2 Billings, GO, 5.00%, 6/15/30

    $ 500      $ 585,015   
    

 

 

  
        1,741,105   

Nebraska — 1.2%

     

Douglas County Hospital Authority No. 3, Refunding RB:

     

5.00%, 11/01/29

      950        1,056,219   

5.00%, 11/01/30

      800        886,560   

Lancaster County Hospital Authority No. 1, Refunding RB, Immanuel Obligation Group, 5.50%, 1/01/30

      1,000        1,094,870   

Nebraska Public Power District, Refunding RB:

     

Series A, 5.00%, 1/01/30

      1,000        1,120,260   

Series A, 5.00%, 1/01/32

      2,000        2,228,140   

Series A-1, 3.00%, 1/01/33

      900        855,468   
    

 

 

  
        7,241,517   

Nevada — 1.6%

     

Clark County Department of Aviation, Refunding RB, 5.00%, 7/01/33

      5,000        5,614,850   

County of Humboldt Nevada, Refunding RB, Idaho Power Co. Project, 5.15%, 12/01/24

      3,800        4,226,474   
    

 

 

  
        9,841,324   

New Jersey — 18.6%

     

County of Essex New Jersey Improvement Authority, LRB, Newark Project, Series A (AGM), 5.00%, 11/01/20

      2,000        2,212,600   

Garden State Preservation Trust, RB, Election of 2005, Series A (AGM), 5.80%, 11/01/15 (c)

      5,050        5,121,306   

New Jersey EDA, RB, AMT:

     

Continental Airlines, Inc. Project, 5.13%, 9/15/23

      6,040        6,577,258   

The Goethals Bridge Replacement Project, Private Activity Bond, 5.50%, 1/01/26

      1,500        1,736,565   

The Goethals Bridge Replacement Project, Private Activity Bond, 5.50%, 1/01/27

      1,000        1,145,860   
Municipal Bonds   

Par  

(000)

     Value  

New Jersey (continued)

     

New Jersey EDA, Refunding RB:

     

New Jersey American Water Co., Series E, AMT, 4.70%, 12/01/25

    $ 3,000      $ 3,223,080   

School Facilities Construction, Series AA, 4.25%, 12/15/24

      3,850        3,904,092   

School Facilities Construction, Series EE, 5.00%, 9/01/23

      3,465        3,734,300   

New Jersey Educational Facilities Authority, RB, Higher Education Facilities Trust Fund, 5.00%, 6/15/28

      10,000        10,472,300   

New Jersey Health Care Facilities Financing Authority, Refunding RB, Hackensack University Medical, Series B (AGM), 4.00%, 1/01/24

      635        674,859   

New Jersey Higher Education Student Assistance Authority, Refunding RB:

     

Series 1, AMT, 5.50%, 12/01/26

      1,665        1,833,898   

Student Loan, Series 1A, 4.75%, 12/01/21

      1,760        1,876,829   

New Jersey State Turnpike Authority, Refunding RB, Series B, 5.00%, 1/01/29

      10,000        11,285,400   

New Jersey Transportation Trust Fund Authority, RB:

     

Series B, 5.25%, 6/15/26

      3,500        3,767,820   

Transportation Program, Series AA, 5.25%, 6/15/31

      12,000        12,688,200   

Transportation System, Series A, 5.25%, 6/15/24

      3,185        3,470,535   

Transportation System, Series B, 5.50%, 6/15/31

      13,970        14,920,658   

Transportation System, Series C, 5.25%, 6/15/32

      12,500        13,249,000   

Newark Housing Authority, RB, Series A:

     

5.00%, 12/01/23

      1,230        1,423,799   

5.00%, 12/01/25

      1,345        1,538,519   

South Jersey Port Corp., RB, Marine Terminal, Series O-1 (AGC), 4.63%, 1/01/23

      1,375        1,474,289   

 

                
   BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015    5

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

New Jersey (concluded)

     

State of New Jersey, GO, Various Purposes, 5.00%, 6/01/28

    $ 5,000      $ 5,663,350   
    

 

 

  
        111,994,517   

New Mexico — 1.3%

     

Albuquerque Bernalillo County Water Utility Authority, Refunding RB, 4.00%, 7/01/33

      4,510        4,743,843   

New Mexico Hospital Equipment Loan Council, Refunding RB, 5.00%, 8/01/31

      2,500        2,805,150   
    

 

 

  
        7,548,993   

New York — 20.2%

     

City of New York New York, GO, Refunding, Series E:

     

Fiscal 2013, 5.00%, 8/01/24

      4,000        4,522,560   

5.00%, 8/01/30

      6,230        7,088,182   

City of New York New York, GO:

     

Series D1, 5.13%, 12/01/26

      4,615        5,069,808   

Sub-Series B-1, 5.25%, 9/01/22

      8,250        9,278,280   

Sub-Series I-1, 5.50%, 4/01/21

      5,000        5,727,700   

County of Essex New York Industrial Development Agency, Refunding RB, International Paper Co. Project, Series A, AMT, 5.20%, 12/01/23

      5,000        5,049,300   

County of Westchester New York Healthcare Corp., Refunding RB, Senior Lien, Remarketing, Series A:

     

5.00%, 11/01/24

      5,470        6,057,150   

5.00%, 11/01/30

      895        964,604   

Long Island Power Authority, Refunding RB, Electric System, Series A, 5.50%, 4/01/24

      1,000        1,108,680   

Metropolitan Transportation Authority, RB:

     

Series B, 5.25%, 11/15/33

      4,405        5,102,840   

Sub-Series B-1, 5.00%, 11/15/24

      2,300        2,714,368   

Sub-Series B-4, 5.00%, 11/15/24

      1,500        1,770,240   

Monroe County Industrial Development Corp., Refunding RB, Series A, 5.00%, 7/01/29

      5,695        6,583,363   

New York City Transitional Finance Authority, BARB, Fiscal 2009, Series S-3, 5.00%, 1/15/23

      3,560        3,986,239   
Municipal Bonds   

Par  

(000)

     Value  

New York (continued)

     

New York City Trust for Cultural Resources, Refunding RB, Carnegie Hall, Series A, 5.00%, 12/01/29

    $ 2,750      $ 3,117,428   

New York State Dormitory Authority, RB:

     

Education, Series D, 5.00%, 9/15/16 (c)

      5        5,261   

Fordham University, Series A, 5.25%, 7/01/25

      900        1,042,569   

Mount Sinai School of Medicine, Series A (NPFGC), 5.15%, 7/01/24

      1,000        1,132,680   

Municipal Health Facilities Lease, Sub-Series 2-4, 5.00%, 1/15/27

      6,900        7,559,226   

New York University Hospitals Center, Series A, 5.00%, 7/01/22

      1,725        1,949,336   

New York University Hospitals Center, Series A, 5.13%, 7/01/23

      1,670        1,896,853   

North Shore-Long Island Jewish Health System, Series A, 5.50%, 5/01/19 (c)

      1,495        1,723,675   

New York State Dormitory Authority, Refunding RB:

     

North Shore-Long Island Jewish Obligated Group, Series E, 5.00%, 5/01/22

      650        722,930   

Yeshiva University, 4.25%, 9/01/24

      2,750        2,750,935   

New York State Urban Development Corp., RB, Service Contract, Series B, 5.00%, 1/01/21

      8,000        8,913,040   

Port Authority of New York & New Jersey, ARB, JFK International Air Terminal LLC Project, 5.00%, 12/01/20

      2,475        2,812,516   

Port Authority of New York & New Jersey, Refunding ARB, Consolidated, 152nd Series, AMT, 5.00%, 11/01/23

      1,000        1,079,150   

Port Authority of New York & New Jersey, Refunding RB:

     

5.00%, 11/01/28

      6,185        7,359,964   

Consolidated, 153rd Series, 5.00%, 7/15/24

      2,010        2,235,663   

 

                
6    BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015   

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

New York (concluded)

  

State of New York Dormitory Authority, RB, Mental Health Services (AGM):

     

5.00%, 8/15/18 (c)

    $ 30      $ 33,682   

5.00%, 2/15/22

      3,950        4,392,163   

5.00%, 8/15/18 (c)

      10        11,227   

2nd Series, 5.00%, 8/15/18 (c)

      10        11,227   

State of New York Dormitory Authority, Refunding RB, North Shore-Long Island Jewish Obligated Group, Series A, 5.00%, 5/01/32

      7,060        7,903,246   
    

 

 

  
        121,676,085   

North Carolina — 0.5%

  

County of Gaston North Carolina Industrial Facilities & Pollution Control Financing Authority, RB, Exempt Facilities, National Gypsum Co. Project, AMT, 5.75%, 8/01/35

      1,105        1,106,834   

North Carolina Medical Care Commission, Refunding RB, WakeMed, Series A, 5.00%, 10/01/31

      1,500        1,646,445   
    

 

 

  
        2,753,279   

Ohio — 1.1%

  

State of Ohio Turnpike Commission, RB, Junior Lien, Infrastructure Projects, Series A-1, 5.25%, 2/15/31

      6,000        6,887,280   

Oklahoma — 0.7%

  

Oklahoma City Public Property Authority, Refunding RB:

     

5.00%, 10/01/27

      1,190        1,381,887   

5.00%, 10/01/28

      1,265        1,455,598   

5.00%, 10/01/29

      1,400        1,602,776   
    

 

 

  
        4,440,261   

Oregon — 1.7%

  

Klamath County School District, GO:

     

5.00%, 6/15/30

      1,000        1,138,520   

5.00%, 6/15/31

      1,000        1,133,280   

Oregon State Facilities Authority, Refunding RB, Series A:

     

Reed College Project, 5.00%, 7/01/29

      1,835        2,090,157   

5.00%, 11/15/29

      1,000        1,134,450   
Municipal Bonds   

Par  

(000)

     Value  

Oregon (concluded)

  

State of Oregon, GO, Series H, 5.00%, 5/01/36

    $ 2,000      $ 2,266,200   

Umatilla County School District No. 16R Pendleton, GO, Series A, 5.00%, 6/15/32

      2,000        2,314,560   
    

 

 

  
        10,077,167   

Pennsylvania — 6.7%

  

City of Philadelphia Pennsylvania, ARB, Series A, AMT, 5.00%, 6/15/20

      2,895        3,103,672   

City of Pittsburgh Pennsylvania, GO, Refunding, Series B (AGM), 5.25%, 9/01/17

      9,630        10,142,412   

County of Allegheny Pennsylvania, GO, Refunding, Series C-68, 5.00%, 11/01/25

      2,515        2,897,532   

County of Allegheny Pennsylvania, GO, Series C-67:

     

5.00%, 11/01/25

      2,700        3,120,876   

5.00%, 11/01/26

      2,375        2,718,425   

Delaware River Joint Toll Bridge Commission, Refunding RB, 5.00%, 7/01/31

      400        458,196   

Pennsylvania Economic Development Financing Authority, RB, The Pennsylvania Rapid Bridge Replacement Project, AMT, 5.00%, 12/31/30

      5,100        5,547,372   

Pennsylvania Turnpike Commission, RB, Sub-Series B, 5.25%, 12/01/31

      4,000        4,420,680   

South Fork Municipal Authority, Refunding RB, Conemaugh Valley Memorial Hospital, Series A (AGC), 6.00%, 7/01/20 (c)

      6,225        7,572,650   
    

 

 

  
        39,981,815   

Puerto Rico — 1.8%

  

Puerto Rico Housing Finance Authority, Refunding RB, M/F Housing, Subordinate, Capital Fund Modernization, 5.13%, 12/01/27

      10,000        10,538,800   

Rhode Island — 2.1%

  

Narragansett Bay Commission, Refunding RB, Series B, 5.00%, 9/01/32

      4,150        4,798,396   

Providence Redevelopment Agency, Refunding RB, Series A, 5.00%, 4/01/29

      1,000        1,085,310   

 

                
   BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015    7

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds    Par  
(000)		     Value  

Rhode Island (concluded)

                 

Rhode Island Clean Water Finance Agency, RB, 5.00%, 10/01/32

    $ 1,435      $ 1,649,303   

Rhode Island Health & Educational Building Corp., RB, City of Newport Issue Financing Program, Series C, 5.00%, 5/15/30

      2,305        2,578,649   

Rhode Island Health & Educational Building Corp., Refunding RB, 5.00%, 9/01/32

      2,000        2,299,100   
    

 

 

  
        12,410,758   

South Dakota — 0.2%

     

South Dakota Health & Educational Facilities Authority, Refunding RB, Regional Health, 5.00%, 9/01/25

      1,000        1,104,700   

Tennessee — 1.3%

     

County of Memphis-Shelby Tennessee Sports Authority, Inc., Refunding RB, Memphis Arena Project:

     

Series A, 5.00%, 11/01/23

      2,695        3,017,538   

Series B, 5.00%, 11/01/22

      1,000        1,122,280   

Knox County Health Educational & Housing Facility Board Tennessee, Refunding RB, Eastowne Village Project, 4.00%, 6/01/31 (b)

      3,420        3,643,155   
    

 

 

  
        7,782,973   

Texas — 8.1%

     

City of Grapevine Texas, GO, 5.00%, 2/15/33

      5,685        6,434,681   

City of Houston Texas, Refunding ARB, Series A:

     

Senior Lien, 5.25%, 7/01/29

      4,055        4,459,892   

Subordinate Lien, AMT, 5.00%, 7/01/25

      1,500        1,683,555   

Subordinate Lien, AMT, 5.00%, 7/01/32

      1,010        1,099,738   

Dallas-Fort Worth International Airport Facilities Improvement Corp., ARB, Series 2001-A-1, AMT, 6.15%, 1/01/16

      4,000        4,015,160   

Dallas/Fort Worth International Airport, Refunding RB, AMT:

     

Series E, 5.00%, 11/01/26

      2,185        2,486,464   

Series E, 5.00%, 11/01/27

      4,960        5,628,509   

Series F, 5.00%, 11/01/31

      6,345        7,081,274   
Municipal Bonds    Par  
(000)		     Value  

Texas (concluded)

                 

Love Field Airport Modernization Corp., RB, Southwest Airlines Co. Project, AMT, 5.00%, 11/01/28

    $ 1,000      $ 1,102,330   

Red River Education Financing Corp., RB, 5.00%, 3/15/33

      1,340        1,508,706   

San Jacinto River Authority, RB, Special Project (AGM), 5.25%, 10/01/25

      2,910        3,266,504   

Socorro ISD, GO, Refunding, School Building (PSF-GTD), 5.00%, 8/15/32

      2,500        2,853,500   

Via Metropolitan Transit Authority, Refunding RB:

     

5.25%, 8/01/28

      1,585        1,795,900   

5.25%, 8/01/29

      1,720        1,936,118   

5.25%, 8/01/33

      3,000        3,337,020   
    

 

 

  
        48,689,351   

U.S. Virgin Islands — 1.9%

     

Virgin Islands Public Finance Authority, Refunding RB:

     

Gross Receipts Taxes Loan Note, Series C, 5.00%, 10/01/30

      5,000        5,424,250   

Series A, 5.25%, 10/01/24

      5,000        6,047,100   
    

 

 

  
        11,471,350   

Vermont — 1.0%

     

University of Vermont & State Agricultural College, Refunding RB, 4.00%, 10/01/30

      5,565        5,852,766   

West Virginia — 1.0%

     

West Virginia Hospital Finance Authority, Refunding RB, Charleston Area Medical Center, Inc., Series A, 5.13%, 9/01/23

      4,000        4,385,520   

West Virginia University, RB, West Virginia University Project, Series B, 5.00%, 10/01/30

      1,500        1,715,310   
    

 

 

  
        6,100,830   

Wisconsin — 2.5%

     

Public Finance Authority, Refunding RB, AMT:

     

National Gypsum Co., 5.25%, 4/01/30

      2,410        2,446,849   

Wisconsin Airport Facilities, Senior Obligated Group, Series B, 5.25%, 7/01/28

      4,765        5,169,548   

WPPI Energy, Refunding RB, Supply System, Series A:

     

5.00%, 7/01/31

      1,600        1,819,184   

 

                
8    BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015   

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

(Percentages shown are based on Net Assets)

 

Municipal Bonds   

Par  

(000)

     Value  

Wisconsin (concluded)

                 

WPPI Energy, Refunding RB, Supply System, Series A (concluded):

     

5.00%, 7/01/32

    $ 1,275      $ 1,444,371   

5.00%, 7/01/33

      3,500        3,924,410   
    

 

 

  
        14,804,362   
Total Municipal Bonds — 137.2%        824,660,081   
    
                  

Municipal Bonds Transferred to

Tender Option Bond Trusts (f)

  

Illinois — 1.6%

     

Du Page & Will Counties Community School District No. 204, GO, School Building, Series A (NPFGC), 5.25%, 12/30/22

      8,650        9,344,244   

Louisiana — 2.4%

     

State of Louisiana, GO, Series A, 5.00%, 8/01/24

      12,000        14,122,800   

Massachusetts — 1.9%

     

Massachusetts Development Finance Agency, Refunding RB, Partners Healthcare, Series L, 5.00%, 7/01/31

      10,175        11,704,599   

Minnesota — 1.9%

     

State of Minnesota, GO, State Various Purposes, Series A, 4.00%, 8/01/29

      10,525        11,706,412   

New York — 8.0%

     

City of New York New York, GO, Refunding, Series E, 5.00%, 8/01/27

      3,507        3,962,709   

City of New York New York, GO, Series I, 5.00%, 3/01/32

      7,009        7,966,497   

City of New York New York Municipal Water Finance Authority, Refunding RB, Water & Sewer System, Series A, 4.75%, 6/15/30

      8,000        8,536,720   

Metropolitan Transportation Authority, RB, Series B, 5.25%, 11/15/25

      4,001        4,608,467   

Municipal Bonds Transferred to

Tender Option Bond Trusts (f)

   

Par  

(000)

     Value  

New York (concluded)

                 

New York State Urban Development Corp., RB, Personal Income Tax, Series A-1, 5.00%, 3/15/32

    $ 5,501      $ 6,297,936   

Port Authority of New York & New Jersey, ARB, Consolidated, 169th Series, AMT, 5.00%, 10/15/26

      5,530        6,298,393   

Port Authority of New York & New Jersey, RB, 178th Series, AMT, 5.00%, 12/01/32

      4,009        4,452,483   

Sales Tax Asset Receivable Corp., Refunding RB, Fiscal 2015, Series A, 5.00%, 10/15/31

      5,010        5,903,233   
    

 

 

  
        48,026,438   

Total Municipal Bonds Transferred to

Tender Option Bond Trusts — 15.8%

  

  

     94,904,493   

Total Long-Term Investments

(Cost — $868,521,045) — 153.0%

  

  

     919,564,574   
    
                  
Short-Term Securities    Shares         

FFI Institutional Tax-Exempt Fund,
0.01% (g)(h)

      14,483,516        14,483,516   

Total Short-Term Securities

(Cost — $14,483,516) — 2.4%

  

  

     14,483,516   
Total Investments (Cost — $883,004,561*) — 155.4%        934,048,090   
Other Assets Less Liabilities — 1.2%        7,094,874   

Liability for TOB Trust Certificates, Including Interest
Expense and Fees Payable — (8.8)%

   

     (52,950,622 ) 
VMTP Shares, at Liquidation Value — (47.8)%        (287,100,000 ) 
    

 

 

  
Net Assets Applicable to Common Shares — 100.0%      $ 601,092,342   
    

 

 

  

 

*   As of July 31, 2015, gross unrealized appreciation and depreciation based on cost for federal income tax purposes were as follows:

 

Tax cost

   $ 832,146,886   
 

 

 

  

Gross unrealized appreciation

   $ 53,202,530   

Gross unrealized depreciation

     (4,233,174 ) 
 

 

 

  

Net unrealized appreciation

   $ 48,969,356   
 

 

 

  

 

                
   BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015    9

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

 

 

Notes to Schedule of Investments

 

(a)   Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933, as amended. These securities may be resold in transactions exempt from registration to qualified institutional investors.

 

(b)   Variable rate security. Rate shown is as of report date.

 

(c)   U.S. Government securities, held in escrow, are used to pay interest on this security, as well as to retire the bond in full at the date indicated, typically at a premium to par.

 

(d)   Issuer filed for bankruptcy and/or is in default of interest payments.

 

(e)   Non-income producing security.

 

(f)   Represent bonds transferred to a TOB Trust in exchange of cash and residual certificates received by the Fund. These bonds serve as collateral in a secured borrowing.

 

(g)   During the period ended July 31, 2015, investments in issuers considered to be an affiliate of the Fund for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

 

Affiliate      Shares Held
at April 30,
2015		       

Net

Activity

       

Shares Held
at July 31,

2015

        Income  

FFI Institutional Tax-Exempt Fund

        1,356,943           13,126,573           14,483,516         $ 471   

 

(h)   Represents the current yield as of report date.

 

Portfolio Abbreviations

 

AGC    Assured Guarantee Corp.              
AGM    Assured Guaranty Municipal Corp.              
AMT    Alternative Minimum Tax (subject to)              
ARB    Airport Revenue Bonds              
BARB    Building Aid Revenue Bonds              
BHAC    Berkshire Hathaway Assurance Corp.              
COP    Certificates of Participation              
EDA    Economic Development Authority              
EDC    Economic Development Corp.              
GARB    General Airport Revenue Bonds              
GO    General Obligation Bonds              
GTD    Guaranteed              
IDA    Industrial Development Authority              
ISD    Independent School District              
LRB    Lease Revenue Bonds              
M/F    Multi-Family              
NPFGC    National Public Finance Guarantee Corp.              
PSF    Public School Fund              
Q-SBLF    Qualified School Bond Loan Fund              
RB    Revenue Bonds              

 

•  

Financial Futures Contracts

 

Contracts
Short		     Issue   Exchange   Expiration  

Notional

Value

     Unrealized
Depreciation		  
  (454 )    10-Year U.S. Treasury Note   Chicago Board of Trade   September 2015   $ 57,856,625      $ (182,449 ) 

 

                
10    BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015   

Schedule of Investments (continued)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

 

Fair Value Hierarchy as of July 31, 2015
•  

Various inputs are used in determining the fair value of investments and derivative financial instruments. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial reporting purposes as follows:

 

  •  

Level 1 — unadjusted price quotations in active markets/exchanges for identical assets or liabilities that the Fund has the ability to access

 

  •  

Level 2 — other observable inputs (including, but not limited to, quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market–corroborated inputs)

 

  •  

Level 3 — unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the Fund’s own assumptions used in determining the fair value of investments and derivative financial instruments)

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The significant unobservable inputs used by the Global Valuation Committee in determining the price for Fair Valued Investments are typically categorized as level 3.

Changes in valuation techniques may result in transfers into or out of an assigned level within the hierarchy. In accordance with the Fund’s policy, transfers between different levels of the fair value hierarchy are deemed to have occurred as of the beginning of the reporting period. The categorization of a value determined for investments and derivative financial instruments is based on the pricing transparency of the investments and derivative financial instruments and is not necessarily an indication of the risks associated with investing in those securities. For information about the Fund’s policy regarding valuation of investments and derivative financial instruments, refer to the Fund’s most recent financial statements as contained in its annual report.

As of July 31, 2015, the following tables summarize the Fund’s investments and derivative financial instruments categorized in the disclosure hierarchy:

 

     Level 1        Level 2        Level 3      Total  

Assets:

  

Investments:

                 

Long-Term Investments1

     —         $ 919,564,574         —      $ 919,564,574   

Short-Term Securities

   $ 14,483,516           —         —        14,483,516   
 

 

 

       

 

 

       

 

     

 

 

  

Total

   $ 14,483,516         $ 919,564,574         —      $ 934,048,090   
 

 

 

       

 

 

       

 

     

 

 

  

1   See above Schedule of Investments for values in each state or political subdivision.

      

     Level 1        Level 2        Level 3      Total  
Derivative Financial Instruments2                 

Liabilities:

  

Interest rate contracts

   $ (182,449 )         —         —      $ (182,449 ) 

2   Derivative financial instruments are financial futures contracts, which are valued at the unrealized appreciation (depreciation) on the instrument.

      

 

                
   BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015    11

Schedule of Investments (concluded)

   

BlackRock Muni Intermediate Duration Fund, Inc. (MUI)

 

The Fund may hold assets and/or liabilities in which the fair value approximates the carrying amount for financial reporting purposes. As of July 31, 2015, such assets and/or liabilities are categorized within the disclosure hierarchy as follows:

 

     Level 1        Level 2        Level 3      Total  

Assets:

  

Cash pledged for financial futures contracts

   $ 612,900           —         —      $ 612,900   

Liabilities:

  

TOB Trust Certificates

     —         $ (52,931,848 )       —        (52,931,848 ) 

VMTP Shares

     —           (287,100,000 )       —        (287,100,000 ) 
 

 

 

       

 

 

       

 

     

 

 

  

Total

   $ 612,900         $ (340,031,848 )       —      $ (339,418,948 ) 
 

 

 

       

 

 

       

 

     

 

 

  

During the period ended July 31, 2015, there were no transfers between levels.

 

                
12    BLACKROCK MUNI INTERMEDIATE DURATION FUND, INC.    JULY 31, 2015   

Item 2   –   Controls and Procedures
2(a) –     The registrant’s principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the “1940 Act”)) are effective as of a date within 90 days of the filing of this report based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act and Rule 13a-15(b) under the Securities Exchange Act of 1934, as amended.
2(b) –     There were no changes in the registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act) that occurred during the registrant’s last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.
Item 3   –   Exhibits
    Certifications – Attached hereto

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

BlackRock Muni Intermediate Duration Fund, Inc.

 

By:      /s/ John M. Perlowski                        
     John M. Perlowski
     Chief Executive Officer (principal executive officer) of  
     BlackRock Muni Intermediate Duration Fund, Inc.

Date: September 22, 2015

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

 

By:      /s/ John M. Perlowski                        
     John M. Perlowski
     Chief Executive Officer (principal executive officer) of  
     BlackRock Muni Intermediate Duration Fund, Inc.

 

Date: September 22, 2015
By:      /s/ Neal J. Andrews                            
     Neal J. Andrews
     Chief Financial Officer (principal financial officer) of  
     BlackRock Muni Intermediate Duration Fund, Inc.
Date: September 22, 2015