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 811-21181

Name of Fund:   BlackRock Municipal 2020 Term Trust (BKK)

Fund Address:   100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: Donald C. Burke, Chief Executive Officer, BlackRock Municipal 2020 Term Trust, 800 Scudders Mill Road, Plainsboro, NJ, 08536. Mailing address: P.O. Box 9011, Princeton, NJ, 08543-9011

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

Date of fiscal year end: 12/31/2008

Date of reporting period: 01/01/2008 – 03/31/2008

Item 1 – Schedule of Investments

 

BlackRock Municipal 2020 Term Trust    
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
      Par            
 State     (000)   Municipal Bonds            Value  
 Alabama - 0.4%   $ 1,165   Courtland, Alabama, IDB, Solid Waste Disposal Revenue        
          Refunding Bonds (International Paper Company Project), Series        
          A, 4.75%, 5/01/17   $ 1,085,745  
 Arizona - 0.9%     1,500   Salt Verde Financial Corporation, Arizona, Senior Gas Revenue        
          Bonds, 5%, 12/01/18     1,479,555  
      1,000   Salt Verde Financial Corporation, Arizona, Senior Gas Revenue        
          Bonds, 5.25%, 12/01/20     983,050  
                2,462,605  
 California - 25.0%     12,000   California State, Various Purpose, GO, 5%, 11/01/22     12,280,920  
      5,000   California Statewide Communities Development Authority Revenue        
          Bonds (John Muir Health), Series A, 5%, 8/15/22     5,016,700  
      12,500   Foothill/Eastern Corridor Agency, California, Toll Road Revenue        
          Refunding Bonds, CABS, 5.953%, 1/15/21 (a)     5,887,875  
      10,000   Foothill/Eastern Corridor Agency, California, Toll Road Revenue        
          Refunding Bonds, CABS, 5.844%, 1/15/22 (a)     4,172,800  
      3,000   Golden State Tobacco Securitization Corporation of California,        
          Tobacco Settlement Revenue Bonds, Series A-1, 6.625%,        
          6/01/13 (b)     3,460,080  
      12,010   Golden State Tobacco Securitization Corporation of California, Tobacco        
          Settlement Revenue Bonds, Series A-1, 6.75%, 6/01/13 (b)     13,922,592  
      975   Golden State Tobacco Securitization Corporation of California,        
          Tobacco Settlement Revenue Bonds, Series A-3, 7.875%,        
          6/01/13 (b)     1,179,048  
      1,470   Golden State Tobacco Securitization Corporation of California,        
          Tobacco Settlement Revenue Bonds, Series A-5, 7.875%,        
          6/01/13 (b)     1,777,642  
      20,000   Golden State Tobacco Securitization Corporation of California, Tobacco        
          Settlement Revenue Bonds, Series B, 5.375%, 6/01/10 (b)     21,091,800  
      6,865   Riverside County, California, Asset Leasing Corporation,        
          Leasehold Revenue Bonds (Riverside County Hospital Project),        
          5.69%, 6/01/25 (a)(c)     2,700,279  
                71,489,736  
 Colorado - 1.7%     4,500   E-470 Public Highway Authority, Colorado Revenue Bonds,        
          CABS, Senior Series B, 5.36%, 9/01/22 (a)(c)     2,041,020  
      3,000   Park Creek Metropolitan District, Colorado, Senior Limited Tax        
          Supported Revenue Refunding Bonds, 5.25%, 12/01/25     2,790,660  
                4,831,680  
 District of     4,215   District of Columbia Tobacco Settlement Financing Corporation,        
 Columbia - 5.1%         Asset-Backed Revenue Refunding Bonds, 6.50%, 5/15/33        
                4,132,850  
Portfolio Abbreviations
To simplify the listings of BlackRock Municipal 2020 Term Trust's portfolio holdings in the Schedule of
Investments, we have abbreviated the names of many of the securities according to the list below.
AMT   Alternative Minimum tax (subject to)   IDB   Industrial Development Board
CABS   Capital Appreciation Bonds   PCR   Pollution Control Revenue Bonds
EDA   Economic Development Authority   M/F   Multi-Family
EDR   Economic Development Revenue   S/F   Single-Family
GO   General Obligation Bonds   VRDN   Variable Rate Demand Notes
IDA   Industrial Development Authority        

1


BlackRock Municipal 2020 Term Trust    
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
      Par            
 State     (000)   Municipal Bonds            Value  
    $ 2,680   District of Columbia, Revenue Refunding Bonds (Friendship Public        
          Charter School, Inc.), 5.75%, 6/01/18 (d)   $ 2,717,198  
      3,320   District of Columbia, Revenue Refunding Bonds (Friendship        
          Public Charter School, Inc.), 5%, 6/01/23 (d)     2,992,117  
      5,000   Metropolitan Washington Airports Authority, D.C., Airport        
          System Revenue Refunding Bonds, AMT, Series C-2, 5%,        
          10/01/24 (e)     4,783,400  
                14,625,565  
 Florida - 12.9%     4,315   Bellalago, Florida, Educational Facilities Benefits District,        
          Capital Improvement Special Assessment Bonds, Series A,        
          5.85%, 5/01/22     4,050,922  
      3,000   CFM Community Development District, Florida, Capital        
          Improvement Revenue Bonds, Series B, 5.875%, 5/01/14     2,712,090  
      4,180   Grand Hampton Community Development District, Florida,        
          Capital Improvement Special Assessment Bonds,        
          6.10%, 5/01/24     4,204,996  
      3,905   Habitat, Florida, Community Development, Special Assessment        
          Bonds, 5.80%, 5/01/25     3,557,728  
      5,475   Miami Beach, Florida, Health Facilities Authority, Hospital        
          Revenue Refunding Bonds (Mount Sinai Medical Center of        
          Florida), 6.75%, 11/15/21     5,567,746  
      4,155   Middle Village Community Development District, Florida,        
          Special Assessment Bonds, Series A, 5.80%, 5/01/22     3,907,279  
      400   Orange County, Florida, Health Facilities Authority, Hospital        
          Revenue Bonds (Orlando Regional Healthcare), VRDN, Series A-        
          10, 1.25%, 10/01/41 (e)(f)     400,000  
      615   Pine Island Community Development District, Florida, Utilities        
          System Revenue Bonds, 5.30%, 11/01/10     597,386  
      3,840   Stevens Plantation Community Development District, Florida, Special        
          Assessment Revenue Bonds, Series B, 6.375%, 5/01/13     3,767,002  
      2,950   Village Community Development District Number 5, Florida,        
          Special Assessment Bonds, Series A, 6%, 5/01/22     2,984,220  
      5,600   Westchester Community Development District Number 1,        
          Florida, Special Assessment Bonds (Community Infrastructure),        
          6%, 5/01/23     5,044,480  
                36,793,849  
 Georgia - 0.7%     2,350   Richmond County, Georgia, Development Authority, Environmental        
          Improvement Revenue Bonds (International Paper Co. Projects), AMT,        
          Series A, 5.75%, 11/01/27     2,103,603  
 Illinois - 12.5%     2,155   Centerpoint Intermodal Center Program Trust, Illinois, Tax        
          Allocation Bonds, Class A, 8%, 6/15/23 (g)     2,013,567  
      5,000   Chicago, Illinois, O'Hare International Airport, General Airport Revenue        
          Bonds, Third Lien, Series A, 5%, 1/01/21 (h)     5,079,900  
      7,000   Chicago, Illinois, O'Hare International Airport, General Revenue        
          Bonds, Third Lien, Series A, 5%, 1/01/22 (h)     7,075,670  
      5,000   Illinois Development Finance Authority Revenue Bonds (Depaul        
          University), Series C, 5.25%, 10/01/24     5,030,050  
      4,800   Illinois Educational Facilities Authority Revenue Bonds        
          (Northwestern University), 5%, 12/01/21     4,943,040  

2


BlackRock Municipal 2020 Term Trust    
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
      Par            
 State     (000)   Municipal Bonds            Value  
  $ 900   Illinois State Finance Authority, Revenue Refunding Bonds        
          (Central DuPage Health System), VRDN, Series B,        
          1.27%, 11/01/38 (f)   $ 900,000  
      3,250   Illinois State Financing Authority, Student Housing Revenue        
          Bonds (MJH Education Assistance IV LLC), Senior Series A,        
          5.50%, 6/01/19 (l)     2,524,015  
      1,075   Illinois State Financing Authority, Student Housing Revenue        
          Bonds (MJH Education Assistance IV LLC), Sub-Series B, 5%,        
          6/01/24 (l)     519,182  
      1,000   Lake, Cook, Kane and McHenry Counties, Illinois, Community        
          Unit School District Number 220, GO, Refunding, 5.25%,        
          12/01/20 (e)     1,103,410  
      13,455   Metropolitan Pier and Exposition Authority, Illinois, Dedicated        
          State Tax Revenue Refunding Bonds (McCormick), Series A,        
          5.26%, 6/15/22 (a)(c)     6,534,017  
                35,722,851  
 Indiana - 5.5%     10,000   Indianapolis, Indiana, Airport Authority, Special Facilities,        
          Revenue Refunding Bonds (Federal Express Corporation        
          Project), AMT, 5.10%, 1/15/17     9,457,200  
      2,000   Lawrence, Indiana, M/F Housing, Revenue Refunding Bonds (Pinnacle        
          Apartments Project), AMT, 5.40%, 6/01/24 (i)     2,000,720  
      4,805   Vincennes, Indiana, EDR, Refunding, 6.25%, 1/01/24     4,407,627  
                15,865,547  
 Kansas - 1.2%     6,440   Unified Government of Wyandotte County and Kansas City, Kansas,        
          Sales Tax Special Obligation Revenue Bonds (Kansas International        
          Speedway Corporation Project), 5.20%, 12/01/20 (a)(c)     3,460,470  
 Kentucky - 0.7%     2,000   Kentucky Housing Corporation, Housing Revenue Bonds, AMT,        
          Series C, 4.625%, 7/01/22     1,873,620  
 Louisiana - 0.6%     2,000   De Soto Parish, Louisiana, Environmental Improvement Revenue        
          Bonds (International Paper Co. Project), AMT, Series A, 5.85%,        
          11/01/27     1,802,660  
 Maryland - 5.7%     3,000   Frederick County, Maryland, Special Obligation Tax Bonds        
          (Urbana Community Development Authority), 6.625%, 7/01/25     3,004,050  
      4,950   Frederick County, Maryland, Special Obligation Tax Bonds        
          (Urbana Community Development Authority), Series A, 5.80%,        
          7/01/20     4,830,952  
      8,500   Maryland State Health and Higher Educational Facilities        
          Authority, Revenue Refunding Bonds (MedStar Health, Inc.),        
          5.375%, 8/15/24     8,349,720  
                16,184,722  
 Massachusetts - 1.6%     4,500   Massachusetts State Development Finance Agency, Solid Waste        
          Disposal Revenue Bonds (Waste Management, Inc. Project),        
          AMT, 5.45%, 6/01/14     4,649,355  
 Michigan - 0.8%     1,060   Macomb County, Michigan, Hospital Finance Authority, Hospital        
          Revenue Refunding Bonds (Mount Clemens General Hospital),        
          VRDN, Series A-1, 1.40%, 10/01/20 (f)     1,060,000  
      1,500   Michigan State Hospital Finance Authority, Hospital Revenue Refunding        
          Bonds (Sparrow Obligated Group), 4.50%, 11/15/26     1,352,400  
                2,412,400  

3


BlackRock Municipal 2020 Term Trust    
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
      Par            
 State     (000)   Municipal Bonds          Value  
 Minnesota - 0.4%   $ 1,250   Minnesota State, Higher Education Facilities Authority Revenue Bonds        
          (University of St. Thomas), Series Five Y, 5%, 10/01/24   $ 1,243,062  
 Mississippi - 0.9%     3,000   Warren County, Mississippi, Environmental Improvement        
          Revenue Bonds (International Paper Company Project), AMT,        
          Series A, 5.85%, 11/01/27     2,703,990  
 Missouri - 3.7%     5,000   Missouri State Development Finance Board, Infrastructure        
          Facilities Revenue Bonds (Branson Landing Project), Series A,        
          5.50%, 12/01/24     4,871,900  
      15   Missouri State Health and Educational Facilities Authority, Educational        
          Facilities Revenue Refunding Bonds (The Washington University), VRDN,        
          Series A, 1.28%, 9/01/30 (f)     15,000  
      5,500   Missouri State Health and Educational Facilities Authority        
          Health Facilities Revenue Refunding Bonds (BJC Health        
          System), Series A, 5%, 5/15/20     5,580,630  
                10,467,530  
 Nevada - 2.2%     5,000   Clark County, Nevada, EDR, Revenue Refunding Bonds (Alexander        
          Dawson School of Nevada Project), 5%, 5/15/20     5,042,900  
      1,765   Henderson, Nevada, Local Improvement Districts, Special        
          Assessment, Series NO T-18, 5.15%, 9/01/21     1,364,822  
                6,407,722  
 New Hampshire -     5,000   New Hampshire Health and Education Facilities Authority, Revenue        
 5.2%         Refunding Bonds (Elliot Hospital), Series B, 5.60%, 10/01/22     5,109,000  
      10,000   New Hampshire State Business Finance Authority, PCR,        
          Refunding (Public Service Company Project), AMT, Series B,        
          4.75%, 5/01/21 (c)     9,610,200  
                14,719,200  
 New Jersey -     1,000   Middlesex County, New Jersey, Improvement Authority Revenue Bonds        
 12.4%         (George Street Student Housing Project), Series A,        
          5%, 8/15/23     969,690  
      11,500   New Jersey EDA, Cigarette Tax Revenue Bonds, 5.50%, 6/15/24     11,046,210  
      7,500   New Jersey EDA, EDR (Kapkowski Road Landfill Reclamation        
          Improvement District Project), AMT, Series B, 6.50%, 4/01/31     7,562,625  
      1,000   New Jersey EDA, First Mortgage Revenue Refunding Bonds (The        
          Winchester Gardens at Ward Homestead Project), Series A,        
          4.80%, 11/01/13     1,012,660  
      5,000   New Jersey EDA, Special Facility Revenue Bonds (Continental        
          Airlines Inc. Project), AMT, 7%, 11/15/30     4,770,850  
      1,500   New Jersey EDA, Special Facility Revenue Bonds (Continental        
          Airlines Inc. Project), AMT, 9%, 6/01/33     1,610,220  
      2,110   New Jersey Health Care Facilities Financing Authority, Revenue        
          Refunding Bonds (AtlantiCare Regional Medical Center), 5%,        
          7/01/20     2,117,596  
      4,000   New Jersey Health Care Facilities Financing Authority, Revenue        
          Refunding Bonds (Capital Health System Inc.), Series A, 5.75%,        
          7/01/23     4,053,760  
      2,500   New Jersey State Housing and Mortgage Finance Agency, S/F Housing        
          Revenue Bonds, AMT, Series T, 4.55%, 10/01/22     2,325,100  
                35,468,711  

4


BlackRock Municipal 2020 Term Trust    
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
      Par            
 State     (000)   Municipal Bonds            Value  
 New York - 8.3%   $ 5,635   New York City, New York, City IDA, Special Facility Revenue        
          Bonds (American Airlines, Inc. - JFK International Airport),        
          AMT, 7.625%, 8/01/25   $ 5,724,597  
      5,000   New York City, New York, City IDA, Special Facility Revenue        
          Bonds (Continental Airlines Inc. Project), AMT, 7.75%, 8/01/31     5,142,250  
      8,500   New York State Energy Research and Development Authority, Gas        
          Facilities Revenue Refunding Bonds (Brooklyn Union Gas        
          Company/Keyspan), AMT, Series A, 4.70%, 2/01/24 (j)     7,823,825  
      5,000   Tobacco Settlement Financing Corporation of New York        
          Revenue Bonds, Series B-1C, 5.50%, 6/01/20     5,174,300  
                23,864,972  
 Ohio - 5.4%     3,000   Cuyahoga County, Ohio, Revenue Refunding Bonds,        
          Series A, 6%, 1/01/19     3,299,250  
      10,000   Cuyahoga County, Ohio, Revenue Refunding Bonds,        
          Series A, 6%, 1/01/20     10,997,499  
      1,060   Pinnacle Community Infrastructure Financing Authority, Ohio,        
          Revenue Bonds, Series A, 6%, 12/01/22     1,017,992  
                15,314,741  
 Oklahoma - 1.2%     3,350   Tulsa, Oklahoma, Municipal Airport Trust, Revenue Refunding        
          Bonds, Series A, 7.75%, 6/01/35     3,445,710  
 Pennsylvania - 5.7%     7,500   Lancaster County, Pennsylvania, Hospital Authority Revenue Bonds        
          (Lancaster General Hospital Project), 5.75%, 9/15/13 (b)     8,396,925  
      1,275   Montgomery County, Pennsylvania, IDA, Revenue Bonds        
          (Whitemarsh Continuing Care Project), 6%, 2/01/21     1,205,117  
      6,680   Pennsylvania State Higher Educational Facilities Authority Revenue        
          Bonds (LaSalle University), 5.50%, 5/01/26     6,649,406  
                16,251,448  
 Rhode Island -     4,500   Rhode Island State Health and Educational Building        
 1.6%         Corporation, Hospital Financing Revenue Bonds (South County        
          Hospital), Series A, 5.875%, 9/15/08 (b)     4,580,730  
 Tennessee - 3.4%     10,000   Tennessee Energy Acquisition Corporation, Gas Revenue Bonds,        
          Series A, 5.25%, 9/01/20     9,669,300  
 Texas - 7.1%     1,100   Brazos River Authority, Texas, PCR, Refunding (TXU Energy        
          Company LLC Project), AMT, Series A, 6.75%, 4/01/38     1,064,481  
      200   Harris County, Texas, Health Facilities Development        
          Corporation, Revenue Bonds (YMCA of the Greater Houston        
          Area), VRDN, 1.30%, 7/01/37 (f)     200,000  
      2,000   North Texas Tollway Authority, System Revenue Refunding        
          Bonds, First Tier, Series A, 6%, 1/01/24     2,097,580  
      3,500   Port Corpus Christi, Texas, Industrial Development Corporation Revenue        
          Refunding Bonds, Series C, 5.40%, 4/01/18     3,397,485  
      7,990   Texas State Turnpike Authority, Central Texas Turnpike System First        
          Tier Revenue Bonds, CABS, Series A, 5.37%, 8/15/21 (a)(h)     3,949,058  
      8,450   Texas State Turnpike Authority, Central Texas Turnpike System First        
          Tier Revenue Bonds, CABS, Series A, 5.51%, 8/15/24 (a)(h)     3,404,674  
      4,040   Weatherford, Texas, Independent School District, GO,        
          Refunding, CABS, 6.876%, 2/15/11 (a)(b)(k)     1,766,288  
      4,040   Weatherford, Texas, Independent School District, GO,        
          Refunding, CABS, 6.906%, 2/15/11 (a)(b)(k)     1,870,560  
      2,905   Weatherford, Texas, Independent School District, GO,        
          Refunding, CABS, 6.906%, 2/15/23 (a)(k)     1,283,894  

5


BlackRock Municipal 2020 Term Trust      
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
      Par            
 State     (000)   Municipal Bonds              Value  
    $ 2,905   Weatherford, Texas, Independent School District, GO,        
          Refunding, CABS, 6.876%, 2/15/24 (a)(k)   $ 1,212,315  
                20,246,335  
 Trust Territories -     4,000   San Manuel Entertainment Authority Series 04-C, 4.50%, 12/01/16     3,811,840  
 1.3%                  
 U.S. Virgin     1,000   Virgin Islands Public Finance Authority, Senior Lien Revenue Bonds        
 Islands - 0.4%         (Matching Fund Loan Note), Series A, 5.25%, 10/01/17     1,030,500  
 Virginia - 7.9%     5,000   Celebrate North Community Development Authority, Virginia, Special        
          Assessment Revenue Bonds, Series B, 6.60%, 3/01/25     4,974,450  
      10,000   Charles City County, Virginia, EDA, Solid Waste Disposal Revenue Bonds        
          (Waste Management, Inc.), AMT, 5.125%, 8/01/27     10,000,700  
      7,500   Mecklenburg County, Virginia, IDA, Exempt Facility Revenue Refunding        
          Bonds (UAE LP Project), 6.50%, 10/15/17     7,821,825  
                22,796,975  
 Washington - 2.9%     10,000   Washington State, Compound Interest Bonds, GO, Series S-5,        
          5.02%, 1/01/19 (a)(j)     6,005,500  
      4,630   Washington State, GO, CABS, Series F, 5.33%, 12/01/21 (a)(c)     2,348,151  
                8,353,651  
 Wisconsin - 2.1%     2,880   Wisconsin State Health and Educational Facilities Authority,        
          Revenue Refunding Bonds (Wheaton Franciscan Services, Inc.),        
          Series A, 5.50%, 8/15/17     2,877,696  
      3,190   Wisconsin State Health and Educational Facilities Authority,        
          Revenue Refunding Bonds (Wheaton Franciscan Services, Inc.),        
          Series A, 5.50%, 8/15/18     3,140,332  
                6,018,028  
 Puerto Rico -     3,300   Puerto Rico Commonwealth, Public Improvement, GO, Series B,        
 5.4%         5.25%, 7/01/17     3,431,835  
      10,900   Puerto Rico Electric Power Authority, Power Revenue Bonds,        
          Series NN, 5.125%, 7/01/13 (b)     12,000,137  
                15,431,972  
          Total Municipal Bonds (Cost - $437,872,558) - 152.8%     437,190,825  
          Corporate Bonds        
 Multi-State - 7.9%     1,000   Charter Mac Equity Issuer Trust, 5.75%, 4/30/15 (g)     1,064,490  
      4,000   Charter Mac Equity Issuer Trust, 6%, 4/30/15 (g)     4,259,440  
      2,500   Charter Mac Equity Issuer Trust, 6%, 4/30/19 (g)     2,669,800  
      2,500   Charter Mac Equity Issuer Trust, 6.30%, 4/30/19 (g)     2,693,200  
                10,686,930  
      5,000   MuniMae TE Bond Subsidiary LLC, 5.40%, 6/29/49 (g)     5,021,850  
      5,000   MuniMae TE Bond Subsidiary LLC, 5.80%, 6/29/49 (g)     4,884,800  
      2,000   MuniMae TE Bond Subsidiary LLC Series D,        
          5.90%, 11/29/49 (g)     1,942,980  
                11,849,630  
          Total Corporate Bonds (Cost - $22,000,000) - 7.9%     22,536,560  
          Total Investments (Cost - $459,872,558*) - 160.7%     459,727,385  
          Other Assets Less Liabilities - 1.4%     4,045,454  
          Preferred Shares, at Redemption Value - (62.1%)     (177,707,173)  
          Net Assets Applicable to Common Shares - 100.0%   $ 286,065,666  

6


BlackRock Municipal 2020 Term Trust    
Schedule of Investments as of March 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
*  The cost and unrealized appreciation (depreciation) of investments as of
  2008, as computed for federal income tax purposes, were as follows:
  Aggregate cost   $ 459,872,558   
  Gross unrealized appreciation   $ 11,400,671 
  Gross unrealized depreciation     (11,504,166)
  Net unrealized depreciation   $ (103,495)
(a)  

Represents a zero coupon bond; the interest rate shown reflects the effective yield at the time of purchase.
(b)  

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

MBIA Insured.
(d)  

ACA Insured.
(e)  

FSA Insured.
(f)  

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

Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in transactions exempt from registration to qualified institutional investors. Unless otherwise indicated, these securities are not considered to be illiquid.
(h)  

AMBAC Insured.
(i)  

FNMA Collateralized.
(j)  

FGIC Insured.
(k)  

PSF Guaranteed.
(l)  

Illiquid security.
 

7


BlackRock Municipal 2020 Term Trust

  • Effective January 1, 2008, the BlackRock Municipal 2020 Term Trust (the “Trust”) adopted FASB Statement of Financial Accounting Standards No. 157, “Fair Value Measurements” (“FAS 157”).
     
     

    FAS 157 clarifies the definition of fair value, establishes a framework for measuring fair values and requires additional disclosures about the use of fair value measurements. Various inputs are used in determining the fair value of investments, which are as follows:
     
        

  • Level 1 – price quotations in active markets/exchanges for identical securities
     
       

  • Level 2 – other observable inputs (including, but not limited to: quoted prices for 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 circumstance, to the extent observable inputs are not available (including the Trust’s own assumptions used in determining the fair value of investments)
     

    The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities. For information about the Trust’s policy regarding valuation of investments and other significant accounting policies, please refer to the Trust’s most recent financial statements as contained in its annual report.

    The following table summarizes the inputs used as of March 31, 2008 in determining the fair valuation of the Trust’s investments:

      Valuation   Investments in
      Inputs   Securities
      Level 1     $ 0  
      Level 2       459,727,385  
      Level 3       0  
      Total     $ 459,727,385  

    8

    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 Municipal 2020 Term Trust

    By:     
    /s/ Donald C. Burke
      Donald C. Burke
      Chief Executive Officer of
      BlackRock Municipal 2020 Term Trust

    Date: May 22, 2008

    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/ Donald C. Burke
      Donald C. Burke
      Chief Executive Officer (principal executive officer) of
      BlackRock Municipal 2020 Term Trust

    Date: May 22, 2008

    By:     
    /s/ Neal J. Andrews
      Neal J. Andrews
      Chief Financial Officer (principal financial officer) of
      BlackRock Municipal 2020 Term Trust

    Date: May 22, 2008