UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-CSRS CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES Investment Company Act file number 811-04077 Name of Fund: Merrill Lynch U.S. Government Mortgage Fund Fund Address: P.O. Box 9011 Princeton, NJ 08543-9011 Name and address of agent for service: Robert C. Doll, Jr., Chief Executive Officer, Merrill Lynch U.S. Government Mortgage Fund, 800 Scudders Mill Road, Plainsboro, NJ, 08536. Mailing address: P.O. Box 9011, Princeton, NJ, 08543-9011 Registrant's telephone number, including area code: (609) 282-2800 Date of fiscal year end: 08/31/05 Date of reporting period: 09/01/04 - 02/28/05 Item 1 - Report to Stockholders Merrill Lynch U.S. Government Mortgage Fund Semi-Annual Report February 28, 2005 (BULL LOGO) Merrill Lynch Investment Managers www.mlim.ml.com Mercury Advisors A Division of Merrill Lynch Investment Managers www.mercury.ml.com This report is not authorized for use as an offer of sale or a solicitation of an offer to buy shares of the Fund unless accompanied or preceded by the Fund's current prospectus. Past performance results shown in this report should not be considered a representation of future performance. Investment return and principal value of shares will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Statements and other information herein are as dated and are subject to change. A description of the policies and procedures that the Fund uses to determine how to vote proxies relating to portfolio securities is available (1) without charge, upon request, by calling toll-free 1-800-MER-FUND (1-800-637-3863); (2) at www.mutualfunds.ml.com; and (3) on the Securities and Exchange Commission's Web site at http://www.sec.gov. Information about how the Fund voted proxies relating to securities held in the Fund's portfolio during the most recent 12-month period ended June 30 is available (1) at www.mutualfunds.ml.com and (2) on the Securities and Exchange Commission's Web site at http://www.sec.gov. Merrill Lynch U.S. Government Mortgage Fund Box 9011 Princeton, NJ 08543-9011 (GO PAPERLESS LOGO) It's Fast, Convenient, & Timely! To sign up today, go to www.icsdelivery.com/live. A Letter From the President Dear Shareholder Financial markets broadly posted positive returns over the most recent reporting period, with international equities providing some of the most impressive results. Total Returns as of February 28, 2005 6-month 12-month U.S. equities (Standard & Poor's 500 Index) + 9.99% + 6.98% International equities (MSCI Europe Australasia Far East Index) +21.18 +18.68 Fixed income (Lehman Brothers Aggregate Bond Index) + 1.26 + 2.43 Tax-exempt fixed income (Lehman Brothers Municipal Bond Index) + 2.40 + 2.96 High yield bonds (Credit Suisse First Boston High Yield Index) + 7.53 +11.21 The U.S. economy has continued to show resilience in the face of the Federal Reserve Board's (the Fed) continued interest rate hikes and, more recently, higher oil prices. The Fed's measured tightening program recently brought the federal funds rate to 2.75% en route to a more "neutral" short-term interest rate target (relative to inflation). Since the U.S. presidential election, progress has been monitored on many fronts in Washington, although concerns remain about the structural problems of debt and deficits, as reflected by a significant decline in the U.S. dollar. U.S. equities ended 2004 in a strong rally, but remained in a fairly narrow trading range for the first two months of 2005. Divergences were notable among sectors, with energy emerging as a clear leader. On the positive side, corporations have accelerated their hiring plans, capital spending remains reasonably robust and merger-and- acquisition activity has increased. Offsetting the positives are slowing corporate earnings growth, renewed energy price concerns and the potential for an economic slowdown. International equities, particularly in Asia, have benefited from higher economic growth rates (China recorded growth of 9.3% in 2004), stronger currencies and relatively reasonable valuations. The major action in the bond market has been a flattening of the yield curve. As short-term interest rates continued to rise, yields on the long end of the curve remained relatively stable - even declining at certain points since the Fed's monetary tightening program began in June 2004. This phenomenon has been largely attributed to continued foreign interest in U.S. bonds, which has served to absorb much of the excess supply. By period-end, many believed long-term yields were long overdue for a rise. Looking ahead, the environment is likely to be a challenging one for investors, with diversification and selectivity becoming increasingly important themes. With this in mind, we encourage you to meet with your financial advisor to review your goals and asset allocation and to rebalance your portfolio, as necessary, to ensure it remains aligned with your objectives and risk tolerance. As always, we thank you for trusting Merrill Lynch Investment Managers with your investment assets, and we look forward to serving you in the months and years ahead. Sincerely, (Robert C. Doll, Jr.) Robert C. Doll, Jr. President and Trustee MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 We are pleased to present to you the management team of Merrill Lynch U.S. Government Mortgage Fund Laura Powers, Frank Viola and Thomas Musmanno are portfolio managers of Merrill Lynch U.S. Government Mortgage Fund. Ms. Powers, who joined Merrill Lynch Investment Managers (MLIM) in 1988, received a bachelor's degree from Winona State University and is a Certified Public Accountant. Mr. Viola, who joined MLIM in 1997, earned a bachelor's degree from The Pennsylvania State University and is a CFA R charterholder, an associate of the Society of Actuaries and a member of the American Academy of Actuaries. Mr. Musmanno, who joined MLIM in 1993, received a bachelor's degree from Siena College and an MBA from St. John's University. He is a CFA charterholder and a member of the Association for Investment Management and Research and the New York Society of Security Analysts. Table of Contents A Letter From the President 2 A Discussion With Your Fund's Portfolio Managers 4 Performance Data 6 Portfolio Information 8 Disclosure of Expenses 9 Schedule of Investments 10 Financial Statements 14 Financial Highlights 17 Notes to Financial Statements 22 Officers and Trustees 27 CFA R and Chartered Financial Analyst R are trademarks owned by the Association for Investment Management and Research. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 A Discussion With Your Fund's Portfolio Managers We ended the period with a positioning that favored commercial, rather than residential mortgages, as we believe this offers the portfolio greater protection against short-term interest rate volatility. How did the Fund perform during the period in light of the existing market conditions? For the six-month period ended February 28, 2005, Merrill Lynch U.S. Government Mortgage Fund's Class A, Class B, Class C, Class I and Class R Shares had total returns of +.82%, +.56%, +.54%, +1.05% and +.80%, respectively. (Fund results shown do not reflect sales charges and would be lower if sales charges were included. Complete performance information can be found on pages 6 - 8 of this report to shareholders.) For the same period, the Fund's unmanaged benchmark, the Citigroup Mortgage Index, returned +1.51%. The economy remained relatively strong throughout the past six months. Gross domestic product (GDP) grew at a rate of 4% in the third quarter of 2004 and 3.8% in the fourth quarter. Real GDP increased 4.4% in 2004 (that is, from the 2003 annual level to the 2004 annual level), compared with an increase of 3% in 2003. Job growth averaged 170,000 per month during the period. Stronger retail sales combined with the year-over-year Consumer Price Index increases averaging 3% monthly caused the Federal Reserve Board (the Fed) to tighten the federal funds rate four times since the end of August. This brought the federal funds rate to 2.50% at period-end, and was followed by another 25 basis point hike on March 22. As short-term interest rates increased, long-term interest rates remained fairly stable, causing a flattening of the yield curve. It appeared that investors believed the Fed was taking a proactive stance against any potential inflation ramifications, supporting higher bond prices and lower yields on the long end and a sell-off on the short end. One of the principal causes of the Fund's underperformance versus the benchmark was our allocation to higher-coupon, short-duration residential mortgages, which we held in anticipation of higher interest rates at the long end of the curve. These securities actually underperformed as the sell-off occurred at the short end of the curve and financing opportunities available in these products diminished during the period. What changes were made to the portfolio during the period? We began selling residential mortgages in favor of commercial mortgages based on our view that short-dated volatility would be increasing in the marketplace, therefore exposing the Fund to the negative convexity associated with residential mortgages (that is, the tendency for these issues to decrease in duration as interest rates decline and increase as they rise). In order to better express our view that the curve would flatten (as measured by the difference between the 10-year and 30-year Treasury), we bought 30-year Treasury bonds and used interest rate swaps to hedge some of the 10-year exposure embedded in the commercial mortgages. In addition to commercial mortgages, we also started buying agency debentures to provide better overall convexity. Agency debentures are the actual debt issued by Fannie Mae or Freddie Mac and normally structured with one principal payment. How would you characterize the Fund's position at the close of the period? Our overall view of the market resulted in the previously mentioned portfolio changes. We expect the Fed to continue to act aggressively against inflation, resulting in a flatter yield curve as short-term interest rates increase, and potentially higher short-term interest rate volatility. This could negatively impact residential mortgage performance. We will continue to overweight securities at the longer end of our maturity range while maintaining a below-average exposure to securities at the shorter end of our maturity range, particularly the two-year sector. We will continue to underweight prepayment- sensitive residential mortgage product in favor of more positively convex agency commercial mortgage-backed product and agency debt. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 We also started to increase the Fund's overall level of yield by purchasing structured investments. Over the next six months - 12 months, we believe yield will play an important role in the overall total return of the Fund. Going forward, we expect to focus more on yield-enhancing securities rather than total return or price return opportunities. Thomas Musmanno Vice President and Co-Portfolio Manager Laura Powers Vice President and Co-Portfolio Manager Frank Viola Vice President and Co-Portfolio Manager March 29, 2005 We are pleased to announce that Thomas Musmanno and Laura Powers have been named Co-Portfolio Managers of the Fund, joining Frank Viola in the day-to-day management of Merrill Lynch U.S. Government Mortgage Fund. Mr. Musmanno has been a Director with Merrill Lynch Investment Managers (MLIM) since 2004 and was a Vice President from 1996 to 2004. He has been the Derivatives and Structured Products Specialist with MLIM since 2000 and has been a portfolio manager in the fixed income management group since 1996. Ms. Powers has been a Director of MLIM since 1998 and was a Vice President thereof from 1993 to 1997. She has been a member of the fixed income management group since 1990. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Performance Data About Fund Performance Investors are able to purchase shares of the Fund through multiple pricing alternatives: * Class A Shares incur a maximum initial sales charge (front-end load) of 4% and an account maintenance fee of 0.25% per year (but no distribution fee). * Class B Shares are subject to a maximum contingent deferred sales charge of 4%, declining to 0% after six years. All Class B Shares purchased prior to December 1, 2002 will maintain the four-year schedule. In addition, Class B Shares are subject to a distribution fee of 0.50% per year and an account maintenance fee of 0.25% per year. These shares automatically convert to Class A Shares after approximately ten years. (There is no initial sales charge for automatic share conversions.) * Class C Shares are subject to a distribution fee of 0.55% per year and an account maintenance fee of 0.25% per year. In addition, Class C Shares are subject to a 1% contingent deferred sales charge if redeemed within one year of purchase. * Class I Shares incur a maximum initial sales charge (front-end load) of 4% and bear no ongoing distribution or account maintenance fees. Class I Shares are available only to eligible investors, as detailed in the Fund's prospectus. * Class R Shares do not incur a maximum sales charge (front-end load) or deferred sales charge. These shares are subject to a distribution fee of 0.25% per year and an account maintenance fee of 0.25% per year. Class R Shares are available only to certain retirement plans. None of the past results shown should be considered a representation of future performance. Current performance may be lower or higher than the performance data quoted. Refer to www.mlim.ml.com to obtain performance data current to the most recent month-end. Performance results do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. Figures shown in each of the following tables assume reinvestment of all dividends and capital gain distributions, if any, at net asset value on the payable date. Investment return and principal value of shares will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Dividends paid to each class of shares will vary because of the different levels of account maintenance, distribution and transfer agency fees applicable to each class, which are deducted from the income available to be paid to shareholders. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Performance Data (continued) Recent Performance Results 10-Year/ 6-Month 12-Month Since Inception Standardized As of February 28, 2005 Total Return Total Return Total Return 30-Day Yield ML U.S. Government Mortgage Fund Class A Shares* +0.82% +1.72% +82.08% 2.61% ML U.S. Government Mortgage Fund Class B Shares* +0.56 +1.19 +73.08 2.20 ML U.S. Government Mortgage Fund Class C Shares* +0.54 +1.14 +72.21 2.15 ML U.S. Government Mortgage Fund Class I Shares* +1.05 +2.07 +86.86 2.85 ML U.S. Government Mortgage Fund Class R Shares* +0.80 +1.47 + 5.63 2.47 Citigroup Mortgage Index** +1.51 +3.33 +97.97/+8.29 -- * Investment results shown do not reflect sales charges; results shown would be lower if a sales charge was included. Cumulative total investment returns are based on changes in net asset values for the periods shown, and assume reinvestment of all dividends and capital gains distributions at net asset value on the payable date. The Fund's 10-year/since inception periods are 10 years for Class A, Class B, Class C and Class I Shares and from 1/03/03 for Class R Shares. ** This unmanaged Index reflects the performance of a capital market weighting of the outstanding agency-issued mortgage-backed securities. Ten-year/since inception total returns are for 10 years and from 1/03/03. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Performance Data (concluded) Average Annual Total Return Return Without Return With Sales Charge Sales Charge** Class A Shares* One Year Ended 2/28/05 +1.72% -2.35% Five Years Ended 2/28/05 +6.29 +5.42 Ten Years Ended 2/28/05 +6.18 +5.74 * Maximum sales charge is 4%. ** Assuming maximum sales charge. Return Return Without CDSC With CDSC** Class B Shares* One Year Ended 2/28/05 +1.19% -2.76% Five Years Ended 2/28/05 +5.74 +5.42 Ten Years Ended 2/28/05 +5.64 +5.64 * Maximum contingent deferred sales charge is 4% and is reduced to 0% after six years. ** Assuming payment of applicable contingent deferred sales charge. Return Return Without CDSC With CDSC** Class C Shares* One Year Ended 2/28/05 +1.14% +0.15% Five Years Ended 2/28/05 +5.69 +5.69 Ten Years Ended 2/28/05 +5.59 +5.59 * Maximum contingent deferred sales charge is 1% and is reduced to 0% after one year. ** Assuming payment of applicable contingent deferred sales charge. Return Without Return With Sales Charge Sales Charge** Class I Shares* One Year Ended 2/28/05 +2.07% -2.01% Five Years Ended 2/28/05 +6.55 +5.68 Ten Years Ended 2/28/05 +6.45 +6.02 * Maximum sales charge is 4%. ** Assuming maximum sales charge. Class R Shares Return One Year Ended 2/28/05 +1.47% Inception (1/03/03) through 2/28/05 +2.58 Portfolio Information as of February 28, 2005 Percent of Asset Mix Total Investments U.S. Government Agency Mortgage-Backed Obligations 59.2% Non-U.S. Government Agency Asset-Backed & Mortgage-Backed Obligations 13.8 U.S. Government Agency Obligations 9.5 Other* 17.5 * Includes portfolio holdings in short-term investments. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Disclosure of Expenses Shareholders of this Fund may incur the following charges: (a) expenses related to transactions, including sales charges, redemption fees and exchange fees; and (b) operating expenses including advisory fees, distribution fees including 12(b)-1 fees, and other Fund expenses. The following example (which is based on a hypothetical investment of $1,000 invested on September 1, 2004 and held through February 28, 2005) is intended to assist shareholders both in calculating expenses based on an investment in the Fund and in comparing these expenses with similar costs of investing in other mutual funds. The first table below provides information about actual account values and actual expenses. In order to estimate the expenses a shareholder paid during the period covered by this report, shareholders can divide their account value by $1,000 and then multiply the result by the number in the first line under the heading entitled "Expenses Paid During the Period." The second table below provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses. In order to assist shareholders in comparing the ongoing expenses of investing in this Fund and other funds, compare the 5% hypothetical example with the 5% hypothetical examples that appear in other funds' shareholder reports. The expenses shown in the table are intended to highlight shareholders ongoing costs only and do not reflect any transactional expenses, such as sales charges, redemption fees or exchange fees. Therefore, the second table is useful in comparing ongoing expenses only, and will not help shareholders determine the relative total expenses of owning different funds. If these transactional expenses were included, shareholder expenses would have been higher. Expenses Paid Beginning Ending During the Period* Account Value Account Value September 1, 2004 September 1, February 28, to February 28, 2004 2005 2005 Actual Class A $1,000 $1,008.20 $4.98 Class B $1,000 $1,005.60 $7.56 Class C $1,000 $1,005.40 $7.81 Class I $1,000 $1,010.50 $3.74 Class R $1,000 $1,008.00 $6.22 Hypothetical (5% annual return before expenses)** Class A $1,000 $1,019.84 $5.01 Class B $1,000 $1,017.26 $7.60 Class C $1,000 $1,017.01 $7.85 Class I $1,000 $1,021.08 $3.76 Class R $1,000 $1,018.60 $6.26 * For each class of the Fund, expenses are equal to the annualized expense ratio for the class (1.00% for Class A, 1.52% for Class B, 1.57% for Class C, .75% for Class I and 1.25% for Class R), multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period shown). ** Hypothetical 5% annual return before expenses is calculated by pro-rating the number of days in the most recent fiscal half-year divided by 365. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Schedule of Investments Face Interest Original Maturity Issue Amount Rate Date(s) Value Non-U.S. Government Agency Asset-Backed & Mortgage-Backed Obligations*--15.9% AmeriCredit Automobile Receivables Trust 04-BM-A2 $ 6,888,415 1.45 % 9/06/2007 $ 6,845,493 Ameriquest Mortgage Securities, Inc. 04-IA1-M1 11,250,000 3.45 (4) 9/25/2034 11,317,667 Bear Stearns Adjustable Rate Mortgage Trust 04-4-A4 47,823,000 3.51 (4) 6/25/2034 46,672,843 CS First Boston Mortgage Securities Corp. 04-TFLA-A2 5,000,000 2.78 (4) 2/15/2014 5,003,384 Centex Home Equity Loan Trust 04-B-AV1 8,967,030 2.85 (4) 3/25/2034 8,967,018 Countrywide Home Equity Loan Trust 04-K-2A 16,473,822 2.89 (4) 2/15/2034 16,502,149 Finance America Mortgage Loan Trust 04-1-2A1 4,667,855 2.82 (4) 6/25/2034 4,667,852 Indymac Home Equity Loan Asset-Backed Trust 04-B-A2A 14,353,865 2.84 (4) 11/25/2034 14,354,668 JPMorgan Chase Commercial Mortgage Securities Corp. 04-FL1A1-A1 24,840,831 2.76 (4) 4/16/2019 24,865,187 MASTR Asset-Backed Securities Trust 04-HE1-A3 20,000,000 3.01 (4) 9/25/2034 20,064,412 Morgan Stanley Capital I 04-XLF-A2 7,500,000 2.82 (4) 4/15/2016 7,526,623 New Century Home Equity Loan Trust 04-3-A5 18,095,000 3.00 (4) 11/25/2034 18,146,001 Option One Mortgage Loan Trust 04-3-A2 5,367,105 2.80 (4) 11/25/2034 5,367,804 Residential Asset Mortgage Products, Inc. 04-RS9-AII2 8,000,000 2.99 (4) 5/25/2034 8,039,244 Residential Asset Securities Corp. 04-KS8-AI1 16,597,340 2.81 (4) 9/25/2022 16,600,233 Securitized Asset-Backed Receivables LLC Trust 04-OP1-A2 11,299,156 2.90 (4) 2/25/2034 11,298,835 Wachovia Bank Commercial Mortgage Trust 04-WL4A-A2 19,794,000 2.76 (4) 10/15/2015 19,816,848 Washington Mutual Pass-Through Certificates 04-AR12-A3 19,280,310 2.82 (4) 10/25/2044 19,434,290 Wells Fargo Home Equity Trust 04-2-A32 20,000,000 2.99 (4) 2/25/2032 20,062,820 Total Non-U.S. Government Agency Mortgage-Backed Obligations (Cost--$285,203,324) 285,553,371 U.S. Government & Agency Obligations--10.9% Fannie Mae 40,000,000 4.625 (c) 10/15/2014 39,890,160 18,000,000 6.25 5/15/2029 20,885,292 Freddie Mac 100,000,000 2.75 (c) 10/15/2006 98,657,700 U.S. Treasury Bonds 27,000,000 5.375 2/15/2031 29,687,337 5,000,000 7.125 2/15/2023 6,408,010 Total U.S. Government & Agency Obligations (Cost--$196,685,502) 195,528,499 U.S. Government Agency Mortgage-Backed Obligations*--68.0% Fannie Mae Guaranteed Pass-Through 24,716,877 4.50 9/01/2034 23,804,034 Certificates 18,210,232 5.00 5/01/2018 - 3/01/2020 18,393,010 19,554,151 5.00 7/01/2034 19,290,797 27,197,162 5.50 3/01/2032 - 3/15/2035 27,419,578 3,979,430 6.50 12/01/2008 - 2/01/2014 4,188,611 1,744,947 6.50 3/01/2033 1,818,325 9,128,834 7.50 7/01/2016 - 12/01/2032 9,775,554 28,056 8.00 9/01/2024 - 9/01/2027 30,321 1,611,806 8.50 (2) 8/01/2012 - 7/15/2023 1,768,443 432,972 11.00 2/01/2011 - 8/01/2020 475,594 303,827 13.00 9/01/2013 - 3/01/2015 343,545 MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Schedule of Investments (continued) Face Interest Original Maturity Issue Amount Rate Date(s) Value U.S. Government Agency Mortgage-Backed Obligations (continued) Fannie Mae Guaranteed Pass-Through $ 5,247,850 4.28% (5) 2/01/2010 $ 5,189,966 Certificates--Multi-Family++ 3,493,712 4.62 (6) 11/01/2014 3,448,197 33,900,000 4.655 (6) 2/01/2015 33,490,488 9,856,000 4.68 (6) 2/01/2015 9,751,921 8,800,000 4.70 3/01/2015 8,715,696 6,482,150 4.72 (6) 3/01/2014 6,427,830 29,561,476 4.86 (6) 1/01/2015 29,682,679 24,200,000 4.86 (6) 2/01/2015 24,154,625 8,000,000 4.94 (6) 3/01/2015 8,060,000 8,995,187 5.01 (6) 1/01/2015 9,099,621 1,226,641 7.18 (3) 2/01/2019 1,350,546 Fannie Mae Guaranteed Pass-Through 03-W19-1A1 2,468,831 2.01 11/25/2033 2,464,088 Certificates--REMICS** 04-T9-A1 24,478,124 2.67 (4) 4/25/2035 24,476,932 04-29-FW 7,761,487 2.83 (4) 12/25/2017 7,773,945 04-61-TF 25,710,447 2.93 (4) 10/25/2031 25,824,465 03-41-YF 21,784,002 2.95 (4) 6/25/2028 21,819,179 Trust 273 330,949 7.00 (1) 7/01/2026 62,987 96-W1-AL 1,658,744 7.25 3/25/2026 1,760,643 Fannie Mae Guranteed Pass-Through 98-M1-IO2 47,621,653 0.686 (1)(4) 2/25/2013 1,239,792 Certificates--REMICS**--Multi-Family++ 97-M8-A2 1,883,014 7.16 (4) 1/25/2022 1,953,017 Freddie Mac Mortgage Participation 332 10.00 7/01/2019 370 Certificates 1,442,603 10.50 1/01/2010 - 9/01/2020 1,615,557 267,669 11.00 8/01/2010 - 9/01/2020 294,566 220,785 11.50 12/01/2011 - 6/01/2020 243,579 170,125 12.00 6/01/2013 - 6/01/2020 189,817 344,161 12.50 12/01/2015 - 7/01/2019 381,031 529,609 13.00 9/01/2010 - 2/01/2016 593,262 Freddie Mac Mortgage Participation 88,653,577 5.00 1/01/2019 - 11/01/2019 89,411,785 Certificates--Gold Program 116,188,953 5.00 12/01/2034 - 2/01/2035 114,776,315 13,147,510 5.50 3/01/2016 - 8/01/2019 13,491,508 199,147,229 5.50 1/01/2035 - 3/15/2035 201,021,609 8,053,348 6.00 3/01/2016 - 6/01/2017 8,372,127 60,283,420 6.00 1/01/2032 - 9/01/2034 61,934,055 3,297,208 6.50 8/01/2029 3,439,372 2,254,456 7.00 4/01/2032 2,376,138 1,468,055 7.50 5/01/2009 - 10/01/2011 1,550,441 23,925,224 7.50 8/01/2017 - 12/01/2032 25,610,508 1,640,300 8.00 1/01/2008 - 7/01/2012 1,736,460 2,779,911 8.00 10/01/2027 - 8/01/2032 2,993,897 407,629 8.50 1/01/2025 - 7/01/2025 449,992 193,994 10.50 10/01/2020 - 12/01/2020 221,639 Freddie Mac Mortgage Participation Trust H013 3,636,839 1.597 5/15/2010 3,597,862 Certificates--REMICS** Trust H016 2,566,620 1.758 1/15/2011 2,550,868 SF4-B 9,392,289 2.37 12/15/2009 9,247,279 Trust 2643-OF 30,192,233 2.94 (4) 7/15/2028 30,275,841 Trust 1220-A 561,699 10.00 2/15/2022 561,864 Trust 1220-B 4,567 874.075 (1)(4) 2/15/2022 55,713 Ginnie Mae MBS Certificates 49,621,195 5.00 12/15/2034 - 1/15/2035 49,445,547 486,096 5.50 3/15/2029 - 4/15/2029 495,665 12,931,460 5.60 1/15/2009 13,249,792 2,977,628 6.00 5/15/2024 - 11/15/2031 3,078,186 25,199,237 6.50 10/15/2023 - 3/15/2032 26,469,622 6,687,364 7.00 4/15/2023 - 4/15/2032 7,085,272 6,899,359 7.50 2/15/2025 - 12/15/2031 7,413,825 4,116,261 8.00 1/15/2024 - 8/15/2026 4,465,343 3,394,870 10.00 2/15/2016 - 12/15/2021 3,821,076 26,723 10.50 1/15/2016 - 4/15/2021 30,499 62 11.00 1/15/2016 69 877 11.50 8/15/2013 982 MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Schedule of Investments (continued) Face Interest Original Maturity Issue Amount Rate Date(s) Value U.S. Government Agency Mortgage-Backed Obligations (concluded) Ginnie Mae MBS Certificates--REMICS** 05-09-IO $ 69,000,000 0.778% (1)(4) 1/16/2045 $ 4,010,625 04-77-IO 168,604,813 1.065 (1)(4) 9/16/2044 9,747,466 03-109-B 40,000,000 3.225 9/16/2021 38,745,576 04-103-A 9,928,287 3.878 12/16/2019 9,784,844 04-77-AB 39,544,736 4.368 11/16/2030 38,906,026 05-10-B 9,636,000 4.404 5/16/2024 9,485,038 04-97-C 8,400,000 4.522 (4) 2/16/2028 8,205,415 05-09-Z 5,000,000 4.65 (4) 1/16/2045 4,350,000 05-12-C 20,000,000 4.658 12/16/2030 19,667,180 05-09-C 8,000,000 4.917 (4) 2/16/2032 7,950,000 02-81-B 10,000,000 5.042 1/16/2029 10,008,857 05-10-ZB 2,750,559 5.175 (4) 12/16/2044 2,646,987 03-109-D 10,000,000 5.252 (4) 1/16/2034 10,087,507 01-58-C 20,000,000 5.499 (4) 8/16/2027 20,711,923 Total U.S. Government Agency Mortgage-Backed Obligations (Cost--$1,225,637,596) 1,220,911,206 Short-Term Securities--20.2% U.S. Government Agency Obligations*** Fannie Mae 20,000,000 2.41 3/14/2005 19,982,594 Freddie Mac 305,000,000 2.42 3/14/2005 304,734,565 Beneficial Interest Merrill Lynch Liquidity Series, LLC Money Market Series (a)(b) $ 31,118,750 31,118,750 Face Amount Issue Repurchase Agreements $6,000,000 Morgan Stanley & Co., Inc. purchased on 2/28/2005 to yield 2.60% to 3/01/2005, repurchase price $6,000,433, collateralized by FNMA, 4.257% due 8/01/2034 6,000,000 Total Short-Term Securities (Cost--$361,835,910) 361,835,909 Total Investments--(Cost--$2,069,362,332++++)--115.0% 2,063,828,985 Liabilities in Excess of Other Assets--(15.0%) (268,599,752) ---------------- Net Assets--100.0% $ 1,795,229,233 ================ ++ Underlying multi-family loans have prepayment protection by means of lockout periods and/or yield maintenance premiums. ++++ The cost and unrealized appreciation (depreciation) of investments as of February 28, 2005, as computed for federal income tax purposes, were as follows: Aggregate cost $ 2,069,451,402 ================= Gross unrealized appreciation $ 5,453,729 Gross unrealized depreciation (11,076,146) ----------------- Net unrealized depreciation $ (5,622,417) ================= * Asset-Backed and Mortgage-Backed Obligations are subject to principal paydowns as a result of prepayments or refinancings of the underlying mortgage instruments. As a result, the average life may be substantially less than the original maturity. ** Real Estate Mortgage Investment Conduits (REMIC). *** U.S. Government Agency Obligations are traded on a discount basis; the interest rate shown reflects the discount rate paid at the time of purchase by the Fund. (1) Represents the interest only portion of a mortgage-backed obligation. (2) Federal Housing Administration/Veterans Administration Mortgages packaged by the Federal National Mortgage Association. (3) Represents a balloon mortgage that amortizes on a 22-year schedule and has a 22-year original maturitiy. (4) Floating rate note. (5) Represents a balloon mortgage that amortizes on a 30-year schedule and has a 7-year original maturity. (6) Represents a balloon mortgage that amortizes on a 30-year schedule and has a 10-year original maturity. (a) Investments in companies considered to be an affiliate of the Fund (such companies are defined as "Affiliated Companies" in Section 2(a)(3) of the Investment Company Act of 1940) were as follows: Interest/ Net Dividend Affiliate Activity Income Merrill Lynch Liquidity Series, LLC Money Market Series $ 31,118,750 $ 9,402 Merrill Lynch Premier Institutional Fund (10,600,000) $ 26,752 (b) Security was purchased with the cash proceeds from securities loans. (c) Security, or a portion of security, is on loan. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Schedule of Investments (concluded) Swaps outstanding as of February 28, 2005 were as follows: Notional Unrealized Amount Appreciation Receive (pay) a variable return equal to the change in the Lehman Brothers Mortgage-Backed Securities Fixed Rate Index Total Return and pay a floating rate based on 1-month USD LIBOR, minus .125% Broker, Lehman Brothers Special Finance Expires March 2005 $100,000,000 -- Receive (pay) a variable return equal to the change in the Lehman Brothers Mortgage-Backed Securities Fixed Rate Index Total Return and pay a floating rate based on 1-month USD LIBOR, minus .125% Broker, Lehman Brothers Special Finance Expires April 2005 $ 72,000,000 -- Receive (pay) a variable return equal to the change in the Lehman Brothers Mortgage-Backed Securities Fixed Rate Index Total Return and pay a floating rate based on 1-month USD LIBOR, minus .125% Broker, Lehman Brothers Special Finance Expires April 2005 $100,000,000 -- Receive (pay) a variable return equal to the change in the Lehman Brothers Mortgage-Backed Securities Fixed Rate Index Total Return and pay a floating rate based on 1-month USD LIBOR, minus .12% Broker, UBS Warburg Expires May 2005 $ 50,000,000 -- Notional Unrealized Amount Appreciation Receive (pay) a variable return equal to the change in the Lehman Brothers Mortgage-Backed Securities Fixed Rate Index Total Return and pay a floating rate based on 1-month USD LIBOR, minus .105% Broker, UBS Warburg Expires August 2005 $ 80,000,000 -- Receive (pay) a variable return equal to the change in the Lehman Brothers Mortgage-Backed Securities Fixed Rate Index Total Return and pay a floating rate based on 1-month USD LIBOR, minus .10% Broker, Lehman Brothers Special Finance Expires September 2005 $100,000,000 -- Receive a variable return equal to 3-month USD LIBOR and pay a fixed rate of 3.4775% Broker, Lehman Brothers Special Finance Expires September 2008 $ 40,000,000 $ 998,286 Receive a variable return equal to 3-month USD LIBOR and pay a fixed rate of 4.3575% Broker, Lehman Brothers Special Finance Expires February 2015 $ 12,000,000 403,604 ----------- Total $ 1,401,890 =========== See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Statement of Assets and Liabilities As of February 28, 2005 Assets Investments in unaffiliated securities, at value (including securities loaned of $29,932,150) (identified cost--$2,038,243,582) $ 2,032,710,235 Investments in affiliated securities, at value (identified cost--$31,118,750) 31,118,750 Unrealized appreciation on swaps 1,401,890 Cash 2,823,351 Receivables: Interest $ 6,711,755 Beneficial interest sold 1,981,785 Principal paydowns 1,127,012 Securities lending 7,173 9,827,725 --------------- Prepaid expenses 80,551 --------------- Total assets 2,077,962,502 --------------- Liabilities Collateral on securities loaned, at value 31,118,750 Payables: Securities purchased 239,454,575 Beneficial interest redeemed 5,748,585 Swaps 3,065,940 Dividends to shareholders 1,043,314 Other affiliates 999,903 Distributor 546,839 Investment adviser 510,687 Variation margin 1,652 251,371,495 --------------- Accrued expenses 243,024 --------------- Total liabilities 282,733,269 --------------- Net Assets Net assets $ 1,795,229,233 =============== Net Assets Consist of Class A Shares of beneficial interest, $.10 par value, unlimited number of shares authorized $ 7,466,114 Class B Shares of beneficial interest, $.10 par value, unlimited number of shares authorized 3,719,688 Class C Shares of beneficial interest, $.10 par value, unlimited number of shares authorized 2,650,521 Class I Shares of beneficial interest, $.10 par value, unlimited number of shares authorized 3,597,994 Class R Shares of beneficial interest, $.10 par value, unlimited number of shares authorized 140,870 Paid-in capital in excess of par 1,775,824,531 Accumulated distributions in excess of investment income--net $ (1,176,021) Undistributed realized capital gains--net 7,136,993 Unrealized depreciation--net (4,131,457) --------------- Total accumulated earnings--net 1,829,515 --------------- Net Assets $ 1,795,229,233 =============== Net Asset Value Class A--Based on net assets of $762,586,483 and 74,661,135 shares of beneficial interest outstanding $ 10.21 =============== Class B--Based on net assets of $379,951,607 and 37,196,875 shares of beneficial interest outstanding $ 10.21 =============== Class C--Based on net assets of $270,704,892 and 26,505,212 shares of beneficial interest outstanding $ 10.21 =============== Class I--Based on net assets of $367,617,499 and 35,979,939 shares of beneficial interest outstanding $ 10.22 =============== Class R--Based on net assets of $14,368,752 and 1,408,704 shares of beneficial interest outstanding $ 10.20 =============== See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Statement of Operations For the Six Months Ended February 28, 2005 Investment Income Interest $ 33,880,236 Securities lending--net 36,154 --------------- Total income 33,916,390 --------------- Expenses Investment advisory fees $ 4,253,952 Account maintenance and distribution fees--Class B 1,536,439 Account maintenance and distribution fees--Class C 1,145,603 Account maintenance fees--Class A 963,997 Transfer agent fees--Class A 828,411 Transfer agent fees--Class B 481,643 Transfer agent fees--Class I 374,206 Transfer agent fees--Class C 343,602 Accounting services 257,021 Custodian fees 105,684 Printing and shareholder reports 54,140 Professional fees 49,134 Pricing fees 48,542 Registration fees 42,278 Trustees' fees and expenses 27,567 Account maintenance and distribution fees--Class R 27,467 Transfer agent fees--Class R 11,749 Other 36,416 --------------- Total expenses 10,587,851 --------------- Investment income--net 23,328,539 --------------- Realized & Unrealized Gain (Loss)--Net Realized gain on: Investments--net 26,920,836 Futures contracts and swaps--net 65,509 Options--net 123,994 Short sales--net 8,281 27,118,620 --------------- Change in unrealized appreciation (depreciation) on: Investments--net (37,047,617) Futures contracts and swaps--net 1,987,351 (35,060,266) --------------- --------------- Total realized and unrealized loss--net (7,941,646) --------------- Net Increase in Net Assets Resulting from Operations $ 15,386,893 =============== See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Statements of Changes in Net Assets For the Six For the Months Ended Year Ended February 28, August 31, Increase (Decrease) in Net Assets: 2005 2004 Operations Investment income--net $ 23,328,539 $ 50,565,902 Realized gain--net 27,118,620 10,222,989 Change in unrealized appreciation (depreciation)--net (35,060,266) 27,462,524 --------------- --------------- Net increase in net assets resulting from operations 15,386,893 88,251,415 --------------- --------------- Dividends to Shareholders Investment income--net: Class A (13,950,294) (23,500,858) Class B (6,306,318) (11,684,031) Class C (4,336,575) (7,884,557) Class I (6,736,564) (10,070,313) Class R (195,070) (83,884) --------------- --------------- Net decrease in net assets resulting from dividends to shareholders (31,524,821) (53,223,643) --------------- --------------- Beneficial Interest Transactions Net decrease in net assets derived from beneficial interest transactions (85,120,105) (328,542,585) --------------- --------------- Net Assets Total decrease in net assets (101,258,033) (293,514,813) Beginning of period 1,896,487,266 2,190,002,079 --------------- --------------- End of period* $ 1,795,229,233 $ 1,896,487,266 =============== =============== * Accumulated distributions in excess of investment income/undistributed investment income--net $ (1,176,021) $ 7,020,261 =============== =============== See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Financial Highlights Class A For the Six Months Ended The following per share data and ratios have been derived February 28, For the Year Ended August 31, from information provided in the financial statements. 2005 2004 2003 2002 2001 Per Share Operating Performance Net asset value, beginning of period $ 10.31 $ 10.13 $ 10.25 $ 9.95 $ 9.44 ---------- ---------- ---------- ---------- ---------- Investment income--net .14++ .27++ .32 .43 .55 Realized and unrealized gain (loss)--net (.05) .19 (.12) .30 .51 ---------- ---------- ---------- ---------- ---------- Total from investment operations .09 .46 .20 .73 1.06 ---------- ---------- ---------- ---------- ---------- Less dividends from investment income--net (.19) (.28) (.32) (.43) (.55) ---------- ---------- ---------- ---------- ---------- Net asset value, end of period $ 10.21 $ 10.31 $ 10.13 $ 10.25 $ 9.95 ========== ========== ========== ========== ========== Total Investment Return** Based on net asset value per share .82%+++ 4.63% 1.93% 7.54% 11.49% ========== ========== ========== ========== ========== Ratios to Average Net Assets Expenses 1.00%* .98% .95% .97% 1.00% ========== ========== ========== ========== ========== Investment income--net 2.72%* 2.65% 3.09% 4.30% 5.59% ========== ========== ========== ========== ========== Supplemental Data Net assets, end of period (in thousands) $ 762,586 $ 798,279 $ 855,543 $ 819,410 $ 729,136 ========== ========== ========== ========== ========== Portfolio turnover 241.44% 508.54% 428.59% 426.77% 199.30% ========== ========== ========== ========== ========== * Annualized. ** Total investment returns exclude the effects of sales charges. ++ Based on average shares outstanding. +++ Aggregate total investment return. See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Financial Highlights (continued) Class B For the Six Months Ended The following per share data and ratios have been derived February 28, For the Year Ended August 31, from information provided in the financial statements. 2005 2004 2003 2002 2001 Per Share Operating Performance Net asset value, beginning of period $ 10.31 $ 10.13 $ 10.26 $ 9.95 $ 9.44 ---------- ---------- ---------- ---------- ---------- Investment income--net .11++ .22++ .26 .38 .50 Realized and unrealized gain (loss)--net (.05) .19 (.13) .31 .51 ---------- ---------- ---------- ---------- ---------- Total from investment operations .06 .41 .13 .69 1.01 ---------- ---------- ---------- ---------- ---------- Less dividends from investment income--net (.16) (.23) (.26) (.38) (.50) ---------- ---------- ---------- ---------- ---------- Net asset value, end of period $ 10.21 $ 10.31 $ 10.13 $ 10.26 $ 9.95 ========== ========== ========== ========== ========== Total Investment Return** Based on net asset value per share .56%+++ 4.09% 1.40% 6.99% 10.91% ========== ========== ========== ========== ========== Ratios to Average Net Assets Expenses 1.52%* 1.50% 1.47% 1.49% 1.52% ========== ========== ========== ========== ========== Investment income--net 2.19%* 2.14% 2.58% 3.76% 5.07% ========== ========== ========== ========== ========== Supplemental Data Net assets, end of period (in thousands) $ 379,952 $ 438,679 $ 591,435 $ 613,282 $ 466,432 ========== ========== ========== ========== ========== Portfolio turnover 241.44% 508.54% 428.59% 426.77% 199.30% ========== ========== ========== ========== ========== * Annualized. ** Total investment returns exclude the effects of sales charges. ++ Based on average shares outstanding. +++ Aggregate total investment return. See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Financial Highlights (continued) Class C For the Six Months Ended The following per share data and ratios have been derived February 28, For the Year Ended August 31, from information provided in the financial statements. 2005 2004 2003 2002 2001 Per Share Operating Performance Net asset value, beginning of period $ 10.31 $ 10.13 $ 10.25 $ 9.95 $ 9.44 ---------- ---------- ---------- ---------- ---------- Investment income--net .11++ .21++ .26 .37 .49 Realized and unrealized gain (loss)--net (.05) .19 (.12) .30 .51 ---------- ---------- ---------- ---------- ---------- Total from investment operations .06 .40 .14 .67 1.00 ---------- ---------- ---------- ---------- ---------- Less dividends from investment income--net (.16) (.22) (.26) (.37) (.49) ---------- ---------- ---------- ---------- ---------- Net asset value, end of period $ 10.21 $ 10.31 $ 10.13 $ 10.25 $ 9.95 ========== ========== ========== ========== ========== Total Investment Return** Based on net asset value per share .54%+++ 4.03% 1.35% 6.94% 10.86% ========== ========== ========== ========== ========== Ratios to Average Net Assets Expenses 1.57%* 1.55% 1.52% 1.54% 1.57% ========== ========== ========== ========== ========== Investment income--net 2.14%* 2.09% 2.52% 3.40% 5.00% ========== ========== ========== ========== ========== Supplemental Data Net assets, end of period (in thousands) $ 270,705 $ 301,532 $ 414,539 $ 384,119 $ 56,706 ========== ========== ========== ========== ========== Portfolio turnover 241.44% 508.54% 428.59% 426.77% 199.30% ========== ========== ========== ========== ========== * Annualized. ** Total investment returns exclude the effects of sales charges. ++ Based on average shares outstanding. +++ Aggregate total investment return. See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Financial Highlights (continued) Class I For the Six Months Ended The following per share data and ratios have been derived February 28, For the Year Ended August 31, from information provided in the financial statements. 2005 2004 2003 2002 2001 Per Share Operating Performance Net asset value, beginning of period $ 10.31 $ 10.13 $ 10.26 $ 9.95 $ 9.44 ---------- ---------- ---------- ---------- ---------- Investment income--net .15++ .29++ .34 .46 .57 Realized and unrealized gain (loss)--net (.04) .20 (.13) .31 .51 ---------- ---------- ---------- ---------- ---------- Total from investment operations .11 .49 .21 .77 1.08 ---------- ---------- ---------- ---------- ---------- Less dividends from investment income--net (.20) (.31) (.34) (.46) (.57) ---------- ---------- ---------- ---------- ---------- Net asset value, end of period $ 10.22 $ 10.31 $ 10.13 $ 10.26 $ 9.95 ========== ========== ========== ========== ========== Total Investment Return** Based on net asset value per share 1.05%+++ 4.89% 2.08% 7.91% 11.77% ========== ========== ========== ========== ========== Ratios to Average Net Assets Expenses .75%* .73% .70% .72% .75% ========== ========== ========== ========== ========== Investment income--net 2.97%* 2.89% 3.34% 4.53% 5.84% ========== ========== ========== ========== ========== Supplemental Data Net assets, end of period (in thousands) $ 367,617 $ 349,958 $ 328,408 $ 296,305 $ 234,930 ========== ========== ========== ========== ========== Portfolio turnover 241.44% 508.54% 428.59% 426.77% 199.30% ========== ========== ========== ========== ========== * Annualized. ** Total investment returns exclude the effects of sales charges. ++ Based on average shares outstanding. +++ Aggregate total investment return. See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Financial Highlights (concluded) Class R For the Period For the Six For the Year January 3, Months Ended Ended 2003++ to The following per share data and ratios have been derived February 28, August 31, August 31, from information provided in the financial statements. 2005 2004 2003 Per Share Operating Performance Net asset value, beginning of period $ 10.29 $ 10.12 $ 10.31 ------------ ------------ ------------ Investment income--net .13+++ .23+++ .24 Realized and unrealized gain (loss)--net (.05) .20 (.19) ------------ ------------ ------------ Total from investment operations .08 .43 .05 ------------ ------------ ------------ Less dividends from investment income--net (.17) (.26) (.24) ------------ ------------ ------------ Net asset value, end of period $ 10.20 $ 10.29 $ 10.12 ============ ============ ============ Total Investment Return** Based on net asset value per share .80%+++++ 4.34% .44%+++++ ============ ============ ============ Ratios to Average Net Assets Expenses 1.25%* 1.21% 1.23%* ============ ============ ============ Investment income--net 2.52%* 2.25% 2.81%* ============ ============ ============ Supplemental Data Net assets, end of period (in thousands) $ 14,369 $ 8,040 $ 77 ============ ============ ============ Portfolio turnover 241.44% 508.54% 428.59% ============ ============ ============ * Annualized. ** Total investment returns exclude the effects of sales charges. ++ Commencement of operations. +++ Based on average shares outstanding. +++++ Aggregate total investment return. See Notes to Financial Statements. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Notes to Financial Statements 1. Significant Accounting Policies: Merrill Lynch U.S. Government Mortgage Fund (the "Fund") is registered under the Investment Company Act of 1940, as amended, as a diversified, open-end management investment company. The Fund's financial statements are prepared in conformity with U.S. generally accepted accounting principles which may require the use of management accruals and estimates. Actual results may differ from these estimates. These unaudited financial statements reflect all adjustments, which are, in the opinion of management, necessary to present a fair statement of the results for the interim period. All such adjustments are of a normal, recurring nature. The Fund offers multiple classes of shares. Shares of Class A and Class I are sold with a front-end sales charge. Shares of Class B and Class C may be subject to a contingent deferred sales charge. Class R Shares are sold only to certain retirement plans. All classes of shares have identical voting, dividend, liquidation and other rights and the same terms and conditions, except that Class A, Class B, Class C and Class R Shares bear certain expenses related to the account maintenance of such shares, and Class B, Class C and Class R Shares also bear certain expenses related to the distribution of such shares. Each class has exclusive voting rights with respect to matters relating to its account maintenance and distribution expenditures (except that Class B shareholders may vote on certain changes to the Class A distribution plan). Income, expenses (other than expenses attributable to a specific class) and realized and unrealized gains and losses are allocated daily to each class based on its relative net assets. The following is a summary of significant accounting policies followed by the Fund. (a) Valuation of investments--Debt securities are traded primarily in the over-the-counter markets and are valued at the last available bid price in the over-the-counter market or on the basis of values obtained by a pricing service. Pricing services use valuation matrixes that incorporate both dealer-supplied valuations and valuation models. The procedures of the pricing service and its valuations are reviewed by the officers of the Fund under the general direction of the Board of Trustees. Such valuations and procedures will be reviewed periodically by the Board of Trustees of the Fund. Financial futures contracts and options thereon, which are traded on exchanges, are valued at their closing prices as of the close of such exchanges. Options written or purchased are valued at the last sale price in the case of exchange-traded options. In the case of options traded in the over-the-counter ("OTC") market, valuation is the last asked price (options written) or the last bid price (options purchased). Swap agreements are valued by quoted fair valuations received daily by the Fund from the counterparty. Short-term investments with a remaining maturity of 60 days or less are valued at amortized cost, which approximates market value, under which method the investment is valued at cost and any premium or discount is amortized on a straight line basis to maturity. Repurchase agreements are valued at cost plus accrued interest. Investments in open-end investment companies are valued at their net asset value each business day. Securities and other assets for which market quotations are not readily available are valued at fair value as determined in good faith by or under the direction of the Board of Trustees of the Fund. Equity securities that are held by the Fund that are traded on stock exchanges or the Nasdaq National Market are valued at the last sale price or official close price on the exchange, as of the close of business on the day the securities are being valued or, lacking any sales, at the last available bid price for long positions, and at the last available ask price for short positions. In cases where equity securities are traded on more than one exchange, the securities are valued on the exchange designated as the primary market by or under the authority of the Board of Trustees of the Fund. Long positions traded in the OTC market, Nasdaq Small Cap or Bulletin Board are valued at the last available bid price obtained from one or more dealers or pricing services approved by the Board of Trustees of the Fund. Short positions traded in the OTC market are valued at the last available ask price. Portfolio securities that are traded both in the OTC market and on a stock exchange are valued according to the broadest and most representative market. Generally, trading in foreign securities is substantially completed each day at various times prior to the close of business on the New York Stock Exchange ("NYSE"). The values of such securities used in computing the net asset value of the Fund's shares are determined as of such times. Foreign currency exchange rates also are generally determined prior to the close of business on the NYSE. Occasionally, events affecting the values of such securities and such exchange rates may occur between the times at which they are determined and the close of business on the NYSE that may not be reflected in the computation of the Fund's net asset value. If events (for example, a company announcement, market volatility or a natural disaster) occur during such periods that are expected to materially affect the value of such securities, those securities may be valued at their fair value as determined in good faith by the Fund's Board of Trustees or by the Investment Adviser using a pricing service and/or procedures approved by the Fund's Board of Trustees. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Notes to Financial Statements (continued) (b) Repurchase agreements--The Fund may invest in U.S. government securities pursuant to repurchase agreements. Under such agreements, the counterparty agrees to repurchase the security at a mutually agreed upon time and price. The Fund takes possession of the underlying securities, marks-to-market such securities and, if necessary, receives additional securities daily to ensure that the contract is fully collateralized. If the counterparty defaults and the fair value of the collateral declines, liquidation of the collateral by the Fund may be delayed or limited. (c) Derivative financial instruments--The Fund may engage in various portfolio investment strategies both to increase the return of the Fund and to hedge, or protect, its exposure to interest rate movements and movements in the securities markets. Losses may arise due to changes in the value of the contract or if the counterparty does not perform under the contract. * Financial futures contracts--The Fund may purchase or sell financial futures contracts and options on such futures contracts. Futures contracts are contracts for delayed delivery of securities at a specific future date and at a specific price or yield. Upon entering into a contract, the Fund deposits and maintains as collateral such initial margin as required by the exchange on which the transaction is effected. Pursuant to the contract, the Fund agrees to receive from or pay to the broker an amount of cash equal to the daily fluctuation in value of the contract. Such receipts or payments are known as variation margin and are recorded by the Fund as unrealized gains or losses. When the contract is closed, the Fund records a realized gain or loss equal to the difference between the value of the contract at the time it was opened and the value at the time it was closed. * Options--The Fund may write and purchase call and put options. When the Fund writes an option, an amount equal to the premium received by the Fund is reflected as an asset and an equivalent liability. The amount of the liability is subsequently marked-to- market to reflect the current market value of the option written. When a security is purchased or sold through an exercise of an option, the related premium paid (or received) is added to (or deducted from) the basis of the security acquired or deducted from (or added to) the proceeds of the security sold. When an option expires (or the Fund enters into a closing transaction), the Fund realizes a gain or loss on the option to the extent of the premiums received or paid (or gain or loss to the extent the cost of the closing transaction exceeds the premiums paid or received). Written and purchased options are non-income producing investments. * Swaps--The Fund may enter into swap agreements, which are over-the- counter contracts in which the Fund and a counterparty agree to make periodic net payments on a specified notional amount. The net payments can be made for a set period of time or may be triggered by a predetermined credit event. The net periodic payments may be based on a fixed or variable interest rate; the change in market value of a specified security, basket of securities, or index; or the return generated by a security. These periodic payments received or made by the Fund are recorded in the accompanying Statement of Operations as realized gains or losses, respectively. Gains or losses are also realized upon termination of the swap agreements. Swaps are marked- to-market daily based on dealer-supplied valuations and changes in value are recorded as unrealized appreciation (depreciation). Risks include changes in the returns of the underlying instruments, failure of the counterparties to perform under the contracts' terms and the possible lack of liquidity with respect to the swap agreements. (d) Income taxes--It is the Fund's policy to comply with the requirements of the Internal Revenue Code applicable to regulated investment companies and to distribute substantially all of its taxable income to its shareholders. Therefore, no federal income tax provision is required. (e) Security transactions and investment income--Security transactions are recorded on the dates the transactions are entered into (the trade dates). Realized gains and losses on security transactions are determined on the identified cost basis. Dividend income is recorded on the ex-dividend dates. Interest income and extended delivery fees are recognized on the accrual basis. The Fund amortizes all premiums and discounts on debt securities. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Notes to Financial Statements (continued) (f) Prepaid registration fees--Prepaid registration fees are charged to expense as the related shares are issued. (g) Dividends and distributions--Dividends from net investment income are declared daily and paid monthly. Distributions of capital gains are recorded on the ex-dividend dates. (h) Securities lending--The Fund may lend securities to financial institutions that provide cash or securities issued or guaranteed by the U.S. government as collateral, which will be maintained at all times in an amount equal to at least 100% of the current market value of the loaned securities. The market value of the loaned securities is determined at the close of business of the Fund and any additional required collateral is delivered to the Fund on the next business day. Where the Fund receives securities as collateral for the loaned securities, it collects a fee from the borrower. The Fund typically receives the income on the loaned securities but does not receive the income on the collateral. Where the Fund receives cash collateral, it may invest such collateral and retain the amount earned on such investment, net of any amount rebated to the borrower. Loans of securities are terminable at any time and the borrower, after notice, is required to return borrowed securities within five business days. The Fund may pay reasonable finder's, lending agent, administrative and custodial fees in connection with its loans. In the event that the borrower defaults on its obligation to return borrowed securities because of insolvency or for any other reason, the Fund could experience delays and costs in gaining access to the collateral. The Fund also could suffer a loss where the value of the collateral falls below the market value of the borrowed securities, in the event of borrower default or in the event of losses on investments made with cash collateral. (i) Mortgage dollar rolls--The Fund may sell mortgage-backed securities for delivery in the current month and simultaneously contract to repurchase substantially similar (same type, coupon and maturity) securities on a specific future date. 2. Investment Advisory Agreement and Transactions with Affiliates: The Fund has entered into an Investment Advisory Agreement with Fund Asset Management, L.P. ("FAM"). The general partner of FAM is Princeton Services, Inc. ("PSI"), an indirect, wholly-owned subsidiary of Merrill Lynch & Co., Inc. ("ML & Co."), which is the limited partner. The Fund has also entered into a Distribution Agreement and Distribution Plan with FAM Distributors, Inc. ("FAMD" or the "Distributor"), which is a wholly-owned subsidiary of Merrill Lynch Group, Inc. FAM is responsible for the management of the Fund's portfolio and provides the necessary personnel, facilities, equipment and certain other services necessary to the operations of the Fund. For such services, the Fund pays a monthly fee based upon the average daily value of the Fund's net assets at the following rate: Portion of Average Daily Value of Net Assets: Rate Not exceeding $500 million .500% In excess of $500 million but not exceeding $1 billion .475% In excess of $1 billion but not exceeding $1.5 billion .450% In excess of $1.5 billion but not exceeding $2 billion .425% In excess of $2 billion but not exceeding $2.5 billion .400% In excess of $2.5 billion but not exceeding $3.5 billion .375% In excess of $3.5 billion but not exceeding $5 billion .350% In excess of $5 billion but not exceeding $6.5 billion .325% Exceeding $6.5 billion .300% Pursuant to the Distribution Plan adopted by the Fund in accordance with Rule 12b-1 under the Investment Company Act of 1940, the Fund pays the Distributor ongoing account maintenance and distribution fees. The fees are accrued daily and paid monthly at annual rates based upon the average daily net assets of the shares as follows: Account Maintenance Distribution Fee Fee Class A .25% -- Class B .25% .50% Class C .25% .55% Class R .25% .25% Pursuant to a sub-agreement with the Distributor, Merrill Lynch, Pierce, Fenner & Smith Incorporated ("MLPF&S"), an affiliate of FAM, also provides account maintenance and distribution services to the Fund. The ongoing account maintenance fee compensates the Distributor and MLPF&S for providing account maintenance services to Class A, Class B, Class C and Class R shareholders. The ongoing distribution fee compensates the Distributor and MLPF&S for providing shareholder and distribution-related services to Class B, Class C and Class R shareholders. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Notes to Financial Statements (continued) For the six months ended February 28, 2005, FAMD earned underwriting discounts and direct commissions and MLPF&S earned dealer concessions on sales of the Fund's Class A and Class I Shares as follows: FAMD MLPF&S Class A $ 1,044 $ 8,848 Class I $ 2 $ 25 For the six months ended February 28, 2005, MLPF&S received contingent deferred sales charges of $283,775 and $3,814 relating to transactions in Class B and Class C Shares, respectively. The Fund has received an exemptive order from the Securities and Exchange Commission permitting it to lend portfolio securities to MLPF&S or its affiliates. Pursuant to that order, the Fund also has retained Merrill Lynch Investment Managers, LLC ("MLIM, LLC"), an affiliate of FAM, as the securities lending agent for a fee based on a share of the returns on investment of cash collateral. MLIM LLC may, on behalf of the Fund, invest cash collateral received by the Fund for such loans, among other things, in a private investment company managed by MLIM, LLC or in registered money market funds advised by FAM or its affiliates. For the six months ended February 28, 2005, MLIM, LLC received $13,561 in securities lending agent fees. For the six months ended February 28, 2005, the Fund reimbursed MLIM $19,508 for certain accounting services. Financial Data Services, Inc. ("FDS"), a wholly-owned subsidiary of ML & Co., is the Fund's transfer agent. Certain officers and/or trustees of the Fund are officers and/or directors of FAM, PSI, FAMD, FDS, and/or ML & Co. 3. Investments: Purchases and sales (including paydowns) of investments, excluding short-term securities, for the six months ended February 28, 2005 were $4,468,899,755 and $4,762,979,032, respectively. 4. Shares of Beneficial Interest: Net decrease in net assets derived from beneficial interest transactions was $85,120,105 and $328,542,585 for the six months ended February 28, 2005 and for the year ended August 31, 2004, respectively. Transactions in shares of beneficial interest for each class were as follows: Class A Shares for the Six Months Ended Dollar February 28, 2005 Shares Amount Shares sold 6,755,429 $ 69,538,143 Automatic conversion of shares 779,106 8,029,832 Shares issued to shareholders in reinvestment of dividends 558,863 5,750,439 -------------- --------------- Total issued 8,093,398 83,318,414 Shares redeemed (10,891,351) (112,136,692) -------------- --------------- Net decrease (2,797,953) $ (28,818,278) ============== =============== Class A Shares for the Year Dollar Ended August 31, 2004 Shares Amount Shares sold 15,955,583 $ 163,141,791 Automatic conversion of shares 2,043,991 20,880,726 Shares issued to shareholders in reinvestment of dividends 1,004,421 10,285,233 -------------- --------------- Total issued 19,003,995 194,307,750 Shares redeemed (26,004,015) (265,728,253) -------------- --------------- Net decrease (7,000,020) $ (71,420,503) ============== =============== Class B Shares for the Six Months Ended Dollar February 28, 2005 Shares Amount Shares sold 2,052,697 $ 21,146,734 Shares issued to shareholders in reinvestment of dividends 450,954 4,639,513 -------------- --------------- Total issued 2,503,651 25,786,247 -------------- --------------- Automatic conversion of shares (779,106) (8,029,832) Shares redeemed (7,091,103) (73,038,690) -------------- --------------- Total redeemed (7,870,209) (81,068,522) -------------- --------------- Net decrease (5,366,558) $ (55,282,275) ============== =============== Class B Shares for the Year Dollar Ended August 31, 2004 Shares Amount Shares sold 5,582,565 $ 57,115,360 Shares issued to shareholders in reinvestment of dividends 844,324 8,648,702 -------------- --------------- Total issued 6,426,889 65,764,062 -------------- --------------- Automatic conversion of shares (20,203,533) (206,479,766) Shares redeemed (2,043,898) (20,880,726) -------------- --------------- Total redeemed (22,247,431) (227,360,492) -------------- --------------- Net decrease (15,820,542) $ (161,596,430) ============== =============== MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Notes to Financial Statements (concluded) Class C Shares for the Six Months Ended Dollar February 28, 2005 Shares Amount Shares sold 1,894,779 $ 19,509,225 Shares issued to shareholders in reinvestment of dividends 314,104 3,231,450 -------------- --------------- Total issued 2,208,883 22,740,675 Shares redeemed (4,964,021) (51,120,032) -------------- --------------- Net decrease (2,755,138) $ (28,379,357) ============== =============== Class C Shares for the Year Dollar Ended August 31, 2004 Shares Amount Shares sold 3,281,754 $ 33,583,925 Shares issued to shareholders in reinvestment of dividends 566,068 5,796,384 -------------- --------------- Total issued 3,847,822 39,380,309 Shares redeemed (15,513,398) (158,579,358) -------------- --------------- Net decrease (11,665,576) $ (119,199,049) ============== =============== Class I Shares for the Six Months Ended Dollar February 28, 2005 Shares Amount Shares sold 8,159,363 $ 84,016,232 Shares issued to shareholders in reinvestment of dividends 20,266 208,548 -------------- --------------- Total issued 8,179,629 84,224,780 Shares redeemed (6,145,870) (63,319,892) -------------- --------------- Net increase 2,033,759 $ 20,904,888 ============== =============== Class I Shares for the Year Dollar Ended August 31, 2004 Shares Amount Shares sold 11,818,884 $ 120,972,566 Shares issued to shareholders in reinvestment of dividends 41,314 423,214 -------------- --------------- Total issued 11,860,198 121,395,780 Shares redeemed (10,323,699) (105,644,634) -------------- --------------- Net increase 1,536,499 $ 15,751,146 ============== =============== Class R Shares for the Six Months Ended Dollar February 28, 2005 Shares Amount Shares sold 874,794 $ 8,998,134 Shares issued to shareholders in reinvestment of dividends 17,872 183,639 -------------- --------------- Total issued 892,666 9,181,773 Shares redeemed (265,178) (2,726,856) -------------- --------------- Net increase 627,488 $ 6,454,917 ============== =============== Class R Shares for the Year Dollar Ended August 31, 2004 Shares Amount Shares sold 949,466 $ 9,714,926 Shares issued to shareholders in reinvestment of dividends 7,660 78,178 -------------- --------------- Total issued 957,126 9,793,104 Shares redeemed (183,511) (1,870,853) -------------- --------------- Net increase 773,615 $ 7,922,251 ============== =============== 5. Short-Term Borrowings: The Fund, along with certain other funds managed by FAM and its affiliates, is a party to a $500,000,000 credit agreement with a group of lenders. The Fund may borrow under the credit agreement to fund shareholder redemptions and for other lawful purposes other than for leverage. The Fund may borrow up to the maximum amount allowable under the Fund's current prospectus and statement of additional information, subject to various other legal, regulatory or contractual limits. The Fund pays a commitment fee of .07% per annum based on the Fund's pro rata share of the unused portion of the credit agreement. Amounts borrowed under the credit agreement bear interest at a rate equal to, at each Fund's election, the federal funds rate plus .50% or a base rate as defined in the credit agreement. The Fund did not borrow under the credit agreement during the six months ended February 28, 2005. On November 26, 2004, the credit agreement was renewed for one year under substantially the same terms. 6. Capital Loss Carryforward: On August 31, 2004, the Fund had a net capital loss carryforward of $8,462,695, of which $4,697,041 expires in 2008 and $3,765,654 expires in 2009. This amount will be available to offset like amounts of any future taxable gains. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Officers and Trustees Robert C. Doll, Jr., President and Trustee James H. Bodurtha, Trustee Joe Grills, Trustee Herbert I. London, Trustee Roberta Cooper Ramo, Trustee Robert S. Salomon, Jr., Trustee Stephen B. Swensrud, Trustee Thomas Musmanno, Vice President Laura Powers, Vice President Frank Viola, Vice President Donald C. Burke, Vice President and Treasurer Jeffrey Hiller, Chief Compliance Officer Alice A. Pellegrino, Secretary Custodian The Bank of New York 100 Church Street New York, NY 10286 Transfer Agent Financial Data Services, Inc. 4800 Deer Lake Drive East Jacksonville, FL 32246-6484 800-637-3863 Andre F. Perold resigned as a Trustee of Merrill Lynch U.S. Government Mortgage Fund effective October 22, 2004. Effective January 1, 2005, Terry K. Glenn retired as President and Trustee of the Fund. The Fund's Board of Trustees wishes Mr. Glenn well in his retirement. Effective January 1, 2005, Robert C. Doll, Jr. became President and Trustee of the Fund. Availability of Quarterly Schedule of Investments The Fund files its complete schedule of portfolio holdings with the Securities and Exchange Commission ("SEC") for the first and third quarters of each fiscal year on Form N-Q. The Fund's Forms N-Q are available on the SEC's Web site at http://www.sec.gov. The Fund's Forms N-Q may also be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330. Electronic Delivery The Fund offers electronic delivery of communications to its shareholders. In order to receive this service, you must register your account and provide us with e-mail information. To sign up for this service, simply access this Web site at http://www.icsdelivery.com/live and follow the instructions. When you visit this site, you will obtain a personal identification number (PIN). You will need this PIN should you wish to update your e-mail address, choose to discontinue this service and/or make any other changes to the service. This service is not available for certain retirement accounts at this time. MERRILL LYNCH U.S. GOVERNMENT MORTGAGE FUND, FEBRUARY 28, 2005 Item 2 - Code of Ethics - Not Applicable to this semi-annual report Item 3 - Audit Committee Financial Expert - Not Applicable to this semi-annual report Item 4 - Principal Accountant Fees and Services - Not Applicable to this semi-annual report Item 5 - Audit Committee of Listed Registrants - Not Applicable Item 6 - Schedule of Investments - Not Applicable Item 7 - Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies - Not Applicable Item 8 - Portfolio Managers of Closed-End Management Investment Companies - Not Applicable Item 9 - Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers - Not Applicable Item 10 - Submission of Matters to a Vote of Security Holders - Not Applicable Item 11 - Controls and Procedures 11(a) - The registrant's certifying officers have reasonably designed such disclosure controls and procedures to ensure material information relating to the registrant is made known to us by others particularly during the period in which this report is being prepared. The registrant's certifying officers have determined that the registrant's disclosure controls and procedures are effective based on our evaluation of these controls and procedures as of a date within 90 days prior to the filing date of this report. 11(b) - There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the Act (17 CFR 270.30a-3(d)) that occurred during the last fiscal half-year of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting. Item 12 - Exhibits attached hereto 12(a)(1) - Code of Ethics - Not Applicable to this semi-annual report 12(a)(2) - Certifications - Attached hereto 12(a)(3) - Not Applicable 12(b) - 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. Merrill Lynch U.S. Government Mortgage Fund By: _/s/ Robert C. Doll, Jr._______ Robert C. Doll, Jr., Chief Executive Officer of Merrill Lynch U.S. Government Mortgage Fund Date: April 22, 2005 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/ Robert C. Doll, Jr.________ Robert C. Doll, Jr., Chief Executive Officer of Merrill Lynch U.S. Government Mortgage Fund Date: April 22, 2005 By: _/s/ Donald C. Burke________ Donald C. Burke, Chief Financial Officer of Merrill Lynch U.S. Government Mortgage Fund Date: April 22, 2005