8-K 1 mab03op2.txt SEPTEMBER 8K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D. C. 20549 Form 8-K Current Report Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 25, 2003 MASTR ASSET BACKED SECURITIES TRUST Mortgage Pass-Through Certificates, Series 2003-OP2 Trust (Exact name of registrant as specified in its charter) New York (governing law of 333-75724-17 54-2114695 Pooling and Servicing Agreement) (Commission 54-2114696 (State or other File Number) IRS EIN jurisdiction of Incorporation) c/o Wells Fargo Bank Minnesota, N.A. 9062 Old Annapolis Road Columbia, MD 21045 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (410) 884-2000 (Former name or former address, if changed since last report) ITEM 5. Other Events On September 25, 2003 a distribution was made to holders of MASTR ASSET BACKED SECURITIES TRUST, Mortgage Pass-Through Certificates, Series 2003-OP2 Trust. ITEM 7. Financial Statements and Exhibits (c) Exhibits furnished in accordance with Item 601(a) of Regulation S-K Exhibit Number Description EX-99.1 Monthly report distributed to holders of Mortgage Pass-Through Certificates, Series 2003-OP2 Trust, relating to the September 25, 2003 distribution. Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. MASTR ASSET BACKED SECURITIES TRUST Mortgage Pass-Through Certificates, Series 2003-OP2 Trust By: Wells Fargo Bank Minnesota, N.A., as Trustee By: /s/ Beth Belfield, Assistant Vice President By: Beth Belfield, Assistant Vice President Date: 10/6/03 INDEX TO EXHIBITS Exhibit Number Description EX-99.1 Monthly report distributed to holders of Mortgage Pass-Through Certificates, Series 2003-OP2 Trust, relating to the September 25, 2003 distribution. EX-99.1

MASTR Asset Backed Securitizations Mortgage Pass-Through Certificates Record Date: 78/31/03 Distribution Date: 89/25/03 MABS Series: 2003-OP2 Contact: Customer Service - CTSLink Wells Fargo Bank Minnesota, N.A. Securities Administration Services 7485 New Horizon Way Frederick, MD 21703 Telephone: (301) 815-6600 Fax: (301) 815-6660 Certificateholder Distribution Summary Certificate Certificate Beginning Class Pass-Through Certificate Interest Principal Class CUSIP Description Rate Balance Distribution Distribution A-1 57643LBC9 SEN 1.~~42000~~43000% ~~297~~293,~~804~~344,~~030~~738.2031 ~~364~~361,~~148~~221.1545 46,~~459~~769,~~291~~295.8937 A-2 57643LBD7 SEN 1.~~43000~~44000% ~~157~~154,~~443~~245,~~894~~995.7883 ~~193~~191,~~874~~265.6603 3,~~197~~817,~~898~~975.9528 A-3 57643LBE5 SEN 1.~~42000~~43000% ~~104~~101,~~404~~517,~~559~~376.8162 ~~127~~125,~~663~~007.5837 23,~~887~~201,~~183~~147.1980 M-1 57643LBF2 MEZ 1.~~85000~~86000% 30,526,000.00 48,~~629~~892.6148 0.00 M-2 57643LBG0 MEZ 2.~~90000~~91000% 23,227,000.00 58,~~002~~202.9899 0.00 M-3 57643LBH8 MEZ 4.~~20000~~21000% 13,272,000.00 48,~~000~~114.4069 0.00 M-4 57643LBJ4 MEZ 4.~~95000~~96000% 6,636,000.00 28,~~285~~343.9509 0.00 M-5 57643LBK1 MEZ 4.~~85000~~86000% 6,636,000.00 27,~~714~~771.5266 0.00 CE MAB3OPT2C OC 0.00000% 5,970,891.14 2,~~685~~635,~~587~~474.7277 0.00 R-1 MAB3OP2R1 RES 0.00000% 0.00 0.00 0.00 R-2 MAB3OP2R2 RES 0.00000% 0.00 0.00 0.00 P MAB3OPT2P Pre_Pay 0.00000% 100.00 ~~188~~324,~~005~~665.9172 0.00 Totals ~~645~~635,~~920~~376,~~475~~101.9390 3,~~769~~848,~~913~~959.4825 1013,~~544~~788,~~374~~418.0345

Certificateholder Distribution Summary (continued) Current Ending Cumulative Realized Certificate Total Realized Class Loss Balance Distribution Losses A-1 0.00 ~~293~~286,~~344~~575,~~738~~442.3194 47,~~823~~130,~~440~~516.0482 0.00 A-2 0.00 ~~154~~150,~~245~~428,~~995~~020.8355 34,~~391~~009,~~773~~240.6131 0.00 A-3 0.00 ~~101~~98,~~517~~316,~~376~~228.6282 3,~~014~~326,~~846~~155.7717 0.00 M-1 0.00 30,526,000.00 48,~~629~~892.6148 0.00 M-2 0.00 23,227,000.00 58,~~002~~202.9899 0.00 M-3 0.00 13,272,000.00 48,~~000~~114.4069 0.00 M-4 0.00 6,636,000.00 28,~~285~~343.9509 0.00 M-5 0.00 6,636,000.00 27,~~714~~771.5266 0.00 CE 0.00 5,970,891.14 2,~~685~~635,~~587~~474.7277 0.00 R-1 0.00 0.00 0.00 0.00 R-2 0.00 0.00 0.00 0.00 P 0.00 100.00 ~~188~~324,~~005~~665.9172 0.00 Totals 0.00 ~~635~~621,~~376~~587,~~101~~683.9045 1417,~~314~~637,~~287~~377.5170 0.00 All distributions required by the Pooling and Servicing Agreement have been calculated by the Certificate Administrator on behalf of the Trustee.

Principal Distribution Statement Original Beginning Scheduled Unscheduled Face Certificate Principal Principal Realized Class Amount Balance Distribution Distribution Accretion Loss (1) A-1 307,739,000.00 ~~297~~293,~~804~~344,~~030~~738.2031 0.00 46,~~459~~769,~~291~~295.8937 0.00 0.00 A-2 163,678,000.00 ~~157~~154,~~443~~245,~~894~~995.7883 0.00 3,~~197~~817,~~898~~975.9528 0.00 0.00 A-3 105,747,000.00 ~~104~~101,~~404~~517,~~559~~376.8162 0.00 23,~~887~~201,~~183~~147.1980 0.00 0.00 M-1 30,526,000.00 30,526,000.00 0.00 0.00 0.00 0.00 M-2 23,227,000.00 23,227,000.00 0.00 0.00 0.00 0.00 M-3 13,272,000.00 13,272,000.00 0.00 0.00 0.00 0.00 M-4 6,636,000.00 6,636,000.00 0.00 0.00 0.00 0.00 M-5 6,636,000.00 6,636,000.00 0.00 0.00 0.00 0.00 CE 5,971,248.86 5,970,891.14 0.00 0.00 0.00 0.00 R-1 0.00 0.00 0.00 0.00 0.00 0.00 R-2 0.00 0.00 0.00 0.00 0.00 0.00 P 100.00 100.00 0.00 0.00 0.00 0.00 Totals 663,432,348.86 ~~645~~635,~~920~~376,~~475~~101.9390 0.00 1013,~~544~~788,~~374~~418.0345 0.00 0.00 (1) Amount Does Not Include Excess Special Hazard, Bankruptcy, or Fraud Losses Unless Otherwise Disclosed. Please Refer to the Prospectus Supplement for a Full Description.

Principal Distribution Statement (continued) Total Ending Ending Total Principal Certificate Certificate Principal Class Reduction Balance Percentage Distribution A-1 46,~~459~~769,~~291~~295.8937 ~~293~~286,~~344~~575,~~738~~442.3194 0.~~95322575~~93122888 46,~~459~~769,~~291~~295.8937 A-2 3,~~197~~817,~~898~~975.9528 ~~154~~150,~~245~~428,~~995~~020.8355 0.~~94237464~~91904850 3,~~197~~817,~~898~~975.9528 A-3 23,~~887~~201,~~183~~147.1980 ~~101~~98,~~517~~316,~~376~~228.6282 0.~~96000243~~92973067 23,~~887~~201,~~183~~147.1980 M-1 0.00 30,526,000.00 1.00000000 0.00 M-2 0.00 23,227,000.00 1.00000000 0.00 M-3 0.00 13,272,000.00 1.00000000 0.00 M-4 0.00 6,636,000.00 1.00000000 0.00 M-5 0.00 6,636,000.00 1.00000000 0.00 CE 0.00 5,970,891.14 0.99994009 0.00 R-1 0.00 0.00 0.00000000 0.00 R-2 0.00 0.00 0.00000000 0.00 P 0.00 100.00 1.00000000 0.00 Totals 1013,~~544~~788,~~374~~418.0345 ~~635~~621,~~376~~587,~~101~~683.9045 0.~~95771046~~93692700 1013,~~544~~788,~~374~~418.0345

Principal Distribution Factors Statement Original Beginning Scheduled Unscheduled Face Certificate Principal Principal Class (2) Amount Balance Distribution Distribution Accretion A-1 307,739,000.00 ~~967~~953.~~71624721~~22574750 0.00000000 1421.~~49049971~~99687193 0.00000000 A-2 163,678,000.00 ~~961~~942.~~91238151~~37463697 0.00000000 1923.~~53774454~~32613595 0.00000000 A-3 105,747,000.00 ~~987~~960.~~30516998~~00242674 0.00000000 2730.~~30274325~~27175996 0.00000000 M-1 30,526,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M-2 23,227,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M-3 13,272,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M-4 6,636,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M-5 6,636,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 CE 5,971,248.86 999.94009293 0.00000000 0.00000000 0.00000000 R-1 0.00 0.00000000 0.00000000 0.00000000 0.00000000 R-2 0.00 0.00000000 0.00000000 0.00000000 0.00000000 P 100.00 1000.00000000 0.00000000 0.00000000 0.00000000 (2) All Classes are per $1000 denomination.

Principal Distribution Factors Statement (continued) Total Ending Ending Total Realized Principal Certificate Certificate Principal Class Loss (3) Reduction Balance Percentage Distribution A-1 0.00000000 1421.~~49049971~~99687193 ~~953~~931.~~22574750~~22887557 0.~~95322575~~93122888 1421.~~49049971~~99687193 A-2 0.00000000 1923.~~53774454~~32613595 ~~942~~919.~~37463697~~04850102 0.~~94237464~~91904850 1923.~~53774454~~32613595 A-3 0.00000000 2730.~~30274325~~27175996 ~~960~~929.~~00242674~~73066678 0.~~96000243~~92973067 2730.~~30274325~~27175996 M-1 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M-2 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M-3 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M-4 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M-5 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 CE 0.00000000 0.00000000 999.94009293 0.99994009 0.00000000 R-1 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 R-2 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 P 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 (3) Amount Does Not Include Excess Special Hazard, Bankrupcy, or Fraud Losses Unless Otherwise Disclosed. Please Refer to the Prospectus Supplement for a Full Description.

Interest Distribution Statement Beginning Payment of Original Current Certificate/ Current Unpaid Current Face Certificate Notional Accrued Interest Interest Class Amount Rate Balance Interest Shortfall Shortfall A-1 307,739,000.00 1.~~42000~~43000% ~~297~~293,~~804~~344,~~030~~738.2031 ~~364~~361,~~148~~221.1545 0.00 0.00 A-2 163,678,000.00 1.~~43000~~44000% ~~157~~154,~~443~~245,~~894~~995.7883 ~~193~~191,~~874~~265.6603 0.00 0.00 A-3 105,747,000.00 1.~~42000~~43000% ~~104~~101,~~404~~517,~~559~~376.8162 ~~127~~125,~~663~~007.5837 0.00 0.00 M-1 30,526,000.00 1.~~85000~~86000% 30,526,000.00 48,~~629~~892.6148 0.00 0.00 M-2 23,227,000.00 2.~~90000~~91000% 23,227,000.00 58,~~002~~202.9899 0.00 0.00 M-3 13,272,000.00 4.~~20000~~21000% 13,272,000.00 48,~~000~~114.4069 0.00 0.00 M-4 6,636,000.00 4.~~95000~~96000% 6,636,000.00 28,~~285~~343.9509 0.00 0.00 M-5 6,636,000.00 4.~~85000~~86000% 6,636,000.00 27,~~714~~771.5266 0.00 0.00 CE 5,971,248.86 0.00000% 5,970,891.14 0.00 0.00 0.00 R-1 0.00 0.00000% 0.00 0.00 0.00 0.00 R-2 0.00 0.00000% 0.00 0.00 0.00 0.00 P 100.00 0.00000% 100.00 0.00 0.00 0.00 Totals 663,432,348.86 ~~896~~888,~~319~~818.8576 0.00 0.00

Interest Distribution Statement (continued) Remaining Ending Non-Supported Total Unpaid Certificate/ Interest Realized Interest Interest Notional Class Shortfall Losses (4) Distribution Shortfall Balance A-1 0.00 0.00 ~~364~~361,~~148~~221.1545 0.00 ~~293~~286,~~344~~575,~~738~~442.3194 A-2 0.00 0.00 ~~193~~191,~~874~~265.6603 0.00 ~~154~~150,~~245~~428,~~995~~020.8355 A-3 0.00 0.00 ~~127~~125,~~663~~007.5837 0.00 ~~101~~98,~~517~~316,~~376~~228.6282 M-1 0.00 0.00 48,~~629~~892.6148 0.00 30,526,000.00 M-2 0.00 0.00 58,~~002~~202.9899 0.00 23,227,000.00 M-3 0.00 0.00 48,~~000~~114.4069 0.00 13,272,000.00 M-4 0.00 0.00 28,~~285~~343.9509 0.00 6,636,000.00 M-5 0.00 0.00 27,~~714~~771.5266 0.00 6,636,000.00 CE 0.00 0.00 2,~~685~~635,~~587~~474.7277 0.00 5,970,891.14 R-1 0.00 0.00 0.00 0.00 0.00 R-2 0.00 0.00 0.00 0.00 0.00 P 0.00 0.00 ~~188~~324,~~005~~665.9172 0.00 100.00 Totals 0.00 0.00 3,~~769~~848,~~913~~959.4825 0.00 (4) Amount Does Not Include Excess Special Hazard, Bankrupcy, or Fraud Losses Unless Otherwise Disclosed. Please Refer to the Prospectus Supplement for a Full Description.

Interest Distribution Factors Statement Beginning Payment of Original Current Certificate/ Current Unpaid Current Face Certificate Notional Accrued Interest Interest Class (5) Amount Rate Balance Interest Shortfall Shortfall A-1 307,739,000.00 1.~~42000~~43000% ~~967~~953.~~71624721~~22574750 1.~~18330192~~17379159 0.00000000 0.00000000 A-2 163,678,000.00 1.~~43000~~44000% ~~961~~942.~~91238151~~37463697 1.~~18448820~~16854452 0.00000000 0.00000000 A-3 105,747,000.00 1.~~42000~~43000% ~~987~~960.~~30516998~~00242674 1.~~20725486~~18213633 0.00000000 0.00000000 M-1 30,526,000.00 1.~~85000~~86000% 1000.00000000 1.~~59305543~~60166678 0.00000000 0.00000000 M-2 23,227,000.00 2.~~90000~~91000% 1000.00000000 2.~~49722220~~50583330 0.00000000 0.00000000 M-3 13,272,000.00 4.~~20000~~21000% 1000.00000000 3.~~61666667~~62527803 0.00000000 0.00000000 M-4 6,636,000.00 4.~~95000~~96000% 1000.00000000 4.~~26250000~~27111061 0.00000000 0.00000000 M-5 6,636,000.00 4.~~85000~~86000% 1000.00000000 4.~~17638939~~18500000 0.00000000 0.00000000 CE 5,971,248.86 0.00000% 999.94009293 0.00000000 0.00000000 0.00000000 R-1 0.00 0.00000% 0.00000000 0.00000000 0.00000000 0.00000000 R-2 0.00 0.00000% 0.00000000 0.00000000 0.00000000 0.00000000 P 100.00 0.00000% 1000.00000000 0.00000000 0.00000000 0.00000000 (5) All Classes are per $1000 denomination.

Interest Distribution Factors Statement (continued) Remaining Ending Non-Supported Total Unpaid Certificate/ Interest Realized Interest Interest Notional Class Shortfall Losses (6) Distribution Shortfall Balance A-1 0.00000000 0.00000000 1.~~18330192~~17379159 0.00000000 ~~953~~931.~~22574750~~22887557 A-2 0.00000000 0.00000000 1.~~18448820~~16854452 0.00000000 ~~942~~919.~~37463697~~04850102 A-3 0.00000000 0.00000000 1.~~20725486~~18213633 0.00000000 ~~960~~929.~~00242674~~73066678 M-1 0.00000000 0.00000000 1.~~59305543~~60166678 0.00000000 1000.00000000 M-2 0.00000000 0.00000000 2.~~49722220~~50583330 0.00000000 1000.00000000 M-3 0.00000000 0.00000000 3.~~61666667~~62527803 0.00000000 1000.00000000 M-4 0.00000000 0.00000000 4.~~26250000~~27111061 0.00000000 1000.00000000 M-5 0.00000000 0.00000000 4.~~17638939~~18500000 0.00000000 1000.00000000 CE 0.00000000 0.00000000 ~~449~~441.~~75310575~~36073237 0.00000000 999.94009293 R-1 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 R-2 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 P 0.00000000 0.00000000 ~~1880059~~3246657.~~10000000~~20000000 0.00000000 1000.00000000 (6) Amount Does Not Include Excess Special Hazard, Bankrupcy,or Fraud Losses Unless Otherwise Disclosed. Please Refer to the Prospectus Supplement for a Full Description.

CERTIFICATEHOLDER ACCOUNT STATEMENT CERTIFICATE ACCOUNT Beginning Balance 0.00 Deposits Payments of Interest and Principal 1417,~~776~~951,~~305~~987.7334 Liquidations, Insurance Proceeds, Reserve Funds 0.00 Proceeds from Repurchased Loans 0.00 Other Amounts (Servicer Advances) 0.00 Realized Loss (Gains, Subsequent Expenses & Recoveries) 0.00 Prepayment Penalties ~~188~~324,~~005~~665.9172 Total Deposits 1418,~~964~~276,~~311~~653.6406 Withdrawals Reimbursement for Servicer Advances 0.00 Payment of Service Fee ~~650~~639,~~024~~275.1336 Payment of Interest and Principal 1417,~~314~~637,~~287~~377.5170 Total Withdrawals (Pool Distribution Amount) 1418,~~964~~276,~~311~~653.6406 Ending Balance 0.00

SERVICING FEES Gross Servicing Fee ~~269~~264,~~133~~739.5299 Radian ~~377~~370,~~122~~829.7600 Trustee Fee- Wells Fargo 3,~~767~~706.8537 Supported Prepayment/Curtailment Interest Shortfall 0.00 Net Servicing Fee ~~650~~639,~~024~~275.1336

OTHER ACCOUNTS Beginning Current Current Ending Account Type Balance Withdrawals Deposits Balance Reserve Fund 1,000.00 0.00 0.0300 1,000.00 Reserve Fund 0.00 0.00 0.00 0.00

LOAN STATUS STRATIFICATION/CREDIT ENHANCEMENT STATEMENT DELINQUENCY STATUS DELINQUENT BANKRUPTCY FORECLOSURE REO Total No of Loans No of Loans No of Loans No of Loans No of Loans Principal Balance Principal Balance Principal Balance Principal Balance Principal Balance 0-29 Days 1213 0 0 1213 1,~~440~~849,~~144~~434.7314 0.00 0.00 1,~~440~~849,~~144~~434.7314 30 Days 4455 12 0 0 4557 68,~~543~~673,~~939~~981.2381 90217,~~038~~935.4094 0.00 0.00 68,~~633~~891,~~977~~917.6375 60 Days 1210 1 1012 0 23 1,~~850~~044,~~190~~635.0481 9560,~~271~~692.0122 12,~~244~~071,~~621~~936.2882 0.00 3,~~190~~177,~~082~~264.3385 90 Days 37 24 1325 0 1836 ~~449~~787,~~302~~959.4707 ~~202~~395,~~462~~460.8627 24,~~136~~072,~~846~~574.0358 0.00 25,~~788~~255,~~611~~993.3692 120 Days 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 150 Days 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 180+ Days 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 Totals 5972 1620 2337 0 98129 810,~~843~~506,~~431~~576.7469 12,~~827~~523,~~917~~522.0057 36,~~381~~144,~~467~~511.3140 0.00 1419,~~052~~174,~~816~~610.0566 No of Loans No of Loans No of Loans No of Loans No of Loans Principal Balance Principal Balance Principal Balance Principal Balance Principal Balance 0-29 Days 0.~~295785~~326715% 0.000000% 0.000000% 0.~~295785~~326715% 0.~~226604~~297450% 0.000000% 0.000000% 0.~~226604~~297450% 30 Days 1.~~084545~~382257% 0.~~024649~~050264% 0.000000% 0.000000% 1.~~109194~~432521% 1.~~029677~~395065% 0.~~014167~~035051% 0.000000% 0.000000% 1.~~043845~~430116% 60 Days 0.~~295785~~251319% 0.~~024649~~025132% 0.~~246488~~301583% 0.000000% 0.~~566921~~578035% 0.~~291124~~168012% 0.~~014991~~009761% 0.~~195839~~333236% 0.000000% 0.~~501954~~511010% 90 Days 0.~~073946~~175924% 0.~~049298~~100528% 0.~~320434~~628299% 0.000000% 0.~~443678~~904750% 0.~~070697~~126730% 0.~~031857~~063603% 0.~~336229~~655005% 0.000000% 0.~~438783~~845339% 120 Days 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 150 Days 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 180+ Days 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% 0.000000% Totals 1.~~454277~~809500% 0.~~394380~~502639% 0.~~566921~~929882% 0.000000% 23.~~415578~~242021% 1.~~391499~~689807% 0.~~287620~~405866% 0.~~532068~~988242% 0.000000% 23.~~211186~~083915%

OTHER INFORMATION Current Period Class A Insufficient Funds 0.00 Principal Balance of Contaminated Properties 0.00 Periodic Advance ~~198~~275,~~766~~232.5411 Class A-1 355,693,248.86 53.61409486% 335,012,140.51 53.89619991% 46.103784% 0.000000% Class A-2 192,015,248.86 28.94270217% 184,584,119.96 29.69558839% 24.200612% 0.000000% Class A-3 86,268,248.86 13.00332265% 86,267,891.14 13.87863586% 15.816953% 0.000000% Class M-1 55,742,248.86 8.40209992% 55,741,891.14 8.96766339% 4.910972% 0.000000% Class M-2 32,515,248.86 4.90106473% 32,514,891.14 5.23094199% 3.736721% 0.000000% Class M-3 19,243,248.86 2.90055933% 19,242,891.14 3.09576455% 2.135177% 0.000000% Class M-4 12,607,248.86 1.90030662% 12,606,891.14 2.02817583% 1.067589% 0.000000% Class CE 0.00 0.00000000% 0.00 0.00000000% 0.960587% 0.000000% Class R-I 0.00 0.00000000% 0.00 0.00000000% 0.000000% 0.000000% Class R-II 0.00 0.00000000% 0.00 0.00000000% 0.000000% 0.000000% Please Refer to the Prospectus Supplement for a Full Description of Loss Exposure

COLLATERAL STATEMENT Collateral Description Mixed Fixed & Arm Weighted Average Gross Coupon 7.~~862141~~863504% Weighted Average Net Coupon 7.~~362141~~363504% Weighted Average Pass-Through Rate 6.~~654517~~656140% Weighted Average Maturity(Stepdown Calculation ) ~~352~~351 Beginning Scheduled Collateral Loan Count 4,~~106~~057 Number Of Loans Paid In Full 4978 Ending Scheduled Collateral Loan Count 43,~~057~~979 Beginning Scheduled Collateral Balance ~~645~~635,~~920~~376,~~475~~101.9390 Ending Scheduled Collateral Balance ~~635~~621,~~376~~587,~~101~~683.9045 Ending Actual Collateral Balance at 31-~~Jul~~Aug-2003 ~~635~~621,~~532~~762,~~955~~015.8506 Monthly P &I Constant 4,~~716~~641,~~983~~650.4756 Special Servicing Fee 0.00 Prepayment Penalties ~~188~~324,~~005~~665.9172 Realized Loss Amount 0.00 Cumulative Realized Loss 0.00 Ending Scheduled Balance for Premium Loans ~~635~~621,~~376~~587,~~101~~683.9045 Scheduled Principal ~~485~~478,~~051~~081.7162 Unscheduled Principal 1013,~~059~~310,~~322~~336.3283

Miscellaneous Reporting Net Monthly Excess Cashflow 2,~~685~~635,~~587~~474.7577 Extra Prinicpal Distribution Amount 0.00 OC Amount 5,970,891.14 OC Deficiency Amount 0.00 OC Release Amount 0.00 OC Target Amount 5,970,891.14 Stepdown NO Trigger Event NO Credit Enhancement Percentage 13.~~577453~~878636%

Group Level Collateral Statement Group Group 1 Group 2 Group 3 Collateral Description Mixed Fixed Mixed ARM Mixed Fixed Weighted Average Coupon Rate 7.~~617950~~618175 8.~~054733~~053807 7.~~549930~~544143 Weighted Average Net Rate 7.~~117950~~118175 7.~~554733~~553807 7.~~049930~~044143 Weighted Average Maturity ~~352~~351 ~~352~~ 351 350 Beginning Loan Count 363 2,~~053~~029 ~~298~~292 Loans Paid In Full 05 2437 6 Ending Loan Count ~~363~~358 21,~~029~~992 ~~292~~286 Beginning Scheduled Balance 49,~~853~~805,~~955~~990.1276 ~~293~~289,~~992~~581,~~446~~119.5805 4342,~~496~~513,~~759~~861.0941 Ending scheduled Balance 4948,~~805~~899,~~990~~678.7650 ~~289~~283,~~581~~718,~~119~~135.0594 4241,~~513~~714,~~861~~170.4154 Record Date 0708/31/2003 0708/31/2003 0708/31/2003 Principal And Interest Constant ~~361~~360,~~196~~292.2170 2,~~180~~147,~~031~~465.8721 ~~312~~305,~~216~~190.4852 Scheduled Principal 44,~~708~~100.7542 ~~206~~203,~~673~~939.0883 3837,~~551~~914.9199 Unscheduled Principal 3862,~~255~~211.6184 45,~~204~~659,~~654~~043.4528 ~~944~~761,~~345~~775.7788 Scheduled Interest 316,~~487~~192.4628 1,~~973~~943,~~358~~525.7938 ~~273~~267,~~664~~275.5753 Servicing Fees 20,~~772~~752.4850 ~~122~~120,~~496~~658.8581 1817,~~123~~714.6410 Master Servicing Fees 0.00 0.00 0.00 Trustee Fee 290.8155 1,~~714~~689.9320 ~~253~~248.7401 FRY Amount 0.00 0.00 0.00 Special Hazard Fee 0.00 0.00 0.00 Other Fee 35,~~386~~352.4366 ~~161~~159,~~647~~161.1837 29,~~863~~449.2365 Pool Insurance Fee 0.00 0.00 0.00 Spread Fee 1 0.00 0.00 0.00 Spread Fee 2 0.00 0.00 0.00 Spread Fee 3 0.00 0.00 0.00 Net Interest 295,~~714~~439.9383 1,~~850~~822,~~861~~866.9561 ~~255~~249,~~540~~561.8744 Realized Loss Amount 0.00 0.00 0.00 Cumulative Realized Loss 0.00 0.00 0.00 Percentage of Cumulative Losses 0.00 0.00 0.00 Prepayment Penalties 0.00 0.00 0.00 Special Servicing Fee 0.00 0.00 0.00 Pass-Through Rate 6.~~259188~~259406 6.~~887931~~887256 6.~~219055~~205894

Group Level Collateral Statement Group Group 4 Group 5 Group 6 Collateral Description Mixed ARM Mixed Fixed Mixed ARM Weighted Average Coupon Rate 8.~~030942~~031824 7.~~235828~~238419 7.~~510324~~521944 Weighted Average Net Rate 7.~~530942~~531824 6.~~735828~~738420 7.~~010324~~021944 Weighted Average Maturity 350 351 ~~352~~351 ~~352~~ Beginning Loan Count ~~963~~953 ~~207~~204 ~~222~~216 Loans Paid In Full 1019 35 6 Ending Loan Count ~~953~~934 ~~204~~199 ~~216~~210 Beginning Scheduled Balance ~~138~~136,~~371~~156,~~551~~549.1184 4342,~~472~~882,~~460~~771.8426 7674,~~733~~435,~~303~~809.1958 Ending scheduled Balance ~~136~~133,~~156~~138,~~549~~265.8443 42,~~882~~033,~~771~~951.2616 7472,~~435~~083,~~809~~481.5888 Record Date 0708/31/2003 0708/31/2003 0708/31/2003 Principal And Interest Constant 1,~~023~~007,~~646~~582.7484 ~~300~~297,~~874~~039.9445 ~~539~~524,~~017~~079.2384 Scheduled Principal 9796,~~601~~261.8064 38,~~742~~369.2388 5857,~~773~~494.9486 Unscheduled Principal 2,~~117~~922,~~399~~022.4777 ~~550~~810,~~947~~450.3522 2,~~238~~294,~~719~~832.6784 Scheduled Interest ~~926~~911,~~044~~321.9420 ~~262~~258,~~132~~669.7157 ~~480~~466,~~243~~584.2998 Servicing Fees 5756,~~654~~731.8286 1817,~~113~~867.5380 31,~~972~~014.2092 Master Servicing Fees 0.00 0.00 0.00 Trustee Fee ~~807~~794.1725 ~~253~~250.5916 ~~447~~434.6120 FRY Amount 0.00 0.00 0.00 Special Hazard Fee 0.00 0.00 0.00 Other Fee 7574,~~633~~602.0250 2928,~~397~~862.8784 4543,~~195~~399.0398 Pool Insurance Fee 0.00 0.00 0.00 Spread Fee 1 0.00 0.00 0.00 Spread Fee 2 0.00 0.00 0.00 Spread Fee 3 0.00 0.00 0.00 Net Interest ~~868~~854,~~390~~589.1930 ~~244~~240,~~019~~801.1568 ~~448~~435,~~271~~570.1609 Realized Loss Amount 0.00 0.00 0.00 Cumulative Realized Loss 0.00 0.00 0.00 Percentage of Cumulative Losses 0.00 0.00 0.00 Prepayment Penalties 0.00 0.00 0.00 Special Servicing Fee 0.00 0.00 0.00 Pass-Through Rate 6.~~868030~~867324 5.~~917338~~923743 6.~~296538~~315281

Group Level Collateral Statement Group Total Collateral Description Mixed Fixed & Arm Weighted Average Coupon Rate 7.~~862141~~863504 Weighted Average Net Rate 7.~~362141~~363504 Weighted Average Maturity ~~352~~351.00 Record Date 0708/31/2003 Principal And Interest Constant 4,~~716~~641,~~983~~650.4756 Beginning Loan Count 4,~~106~~057 Loans Paid In Full 4978 Ending Loan Count 43,~~057~~979 Beginning Scheduled Balance ~~645~~635,~~920~~376,~~475~~101.9390 Ending Scheduled Balance ~~635~~621,~~376~~587,~~101~~683.9045 Scheduled Principal ~~485~~478,~~051~~081.7162 Unscheduled Principal 1013,~~059~~310,~~322~~336.3283 Scheduled Interest 4,~~231~~163,~~931~~568.7694 Servicing Fee ~~269~~264,~~133~~739.5299 Master Servicing Fee 0.00 Trustee Fee 3,~~767~~706.8537 Fry Amount 0.00 Special Hazard Fee 0.00 Other Fee ~~377~~370,~~122~~829.7600 Pool Insurance Fee 0.00 Spread 1 0.00 Spread 2 0.00 Spread 3 0.00 Net Interest 3,~~962~~898,~~798~~828.2595 Realized Loss Amount 0.00 Cumulative Realized Loss 0.00 Percentage of Cumulative Losses 0.00 Prepayment Penalties 0.00 Special Servicing Fee 0.00 Pass-Through Rate 6.~~654517~~656140

Filing Compare · MORTGAGE ASSET SEC TRANS MASTR PASS THRU SER 2003-OPT2