8-K 1 mab04wm1_dec.txt DECEMBER 8-K 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): December 27, 2004 MASTR ASSET BACKED SECURITIES TRUST Mortgage Pass-Through Certificates, Series 2004-WMC1 Trust (Exact name of registrant as specified in its charter) New York (governing law of 333-106982-20 54-2150435 Pooling and Servicing Agreement) (Commission 54-2150436 (State or other File Number) 54-2150437 jurisdiction 54-2150438 of Incorporation) IRS EIN c/o Wells Fargo Bank, 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) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): [ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act(17 CFR 240.14d-2(b)) [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act(17 CFR 240.13e-4(c)) ITEM 8.01 Other Events On December 27, 2004 a distribution was made to holders of MASTR ASSET BACKED SECURITIES TRUST, Mortgage Pass-Through Certificates, Series 2004-WMC1 Trust. ITEM 9.01 Financial Statements and Exhibits (c) Exhibits Exhibit Number Description EX-99.1 Monthly report distributed to holders of Mortgage Pass-Through Certificates, Series 2004-WMC1 Trust, relating to the December 27, 2004 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 2004-WMC1 Trust (Registrant) By: Wells Fargo Bank, N.A. as Master Servicer By: /s/ Beth Belfield as Assistant Vice President By: Beth Belfield as Assistant Vice President Date: 12/31/2004 INDEX TO EXHIBITS Exhibit Number Description EX-99.1 Monthly report distributed to holders of Mortgage Pass-Through Certificates, Series 2004-WMC1 Trust, relating to the December 27, 2004 distribution. EX-99.1

MASTR Asset Backed Securitizations Mortgage Pass-Through Certificates Record Date: 1011/3130/2004 Distribution Date: 1112/2627/2004 ~~MABS~~MASTR Asset Backed Securitizations Mortgage Pass-Through Certificates Series: 2004-~~WM1~~WMC1 Contact: Customer Service - CTSLink Wells Fargo Bank, 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 A1 57643LCQ7 SEN 2.~~15250~~40000% ~~175~~157,~~869~~404,~~919~~072.6369 ~~336~~325,~~497~~301.7875 1820,~~465~~307,~~846~~995.9488 A2 57643LCR5 SEN 2.~~31250~~56000% 28,170,000.00 5762,~~905~~099.0020 0.00 A3 57643LCS3 SEN 2.~~16250~~41000% ~~107~~98,~~166~~366,~~242~~312.1136 ~~205~~204,~~997~~137.3342 86,~~799~~893,~~929~~599.7507 A4 57643LCT1 SEN 2.~~03250~~28000% 2816,~~204~~241,~~708~~299.3701 5031,~~956~~887.5108 1110,~~963~~229,~~409~~332.3601 A5 57643LCU8 SEN 2.~~15250~~40000% 79,850,000.00 ~~152~~165,~~779~~023.6733 0.00 A6 57643LCV6 SEN 2.~~33250~~58000% 17,315,000.00 3538,~~899~~468.7716 0.00 M1 57643LCW4 MEZ 2.~~45250~~70000% 52,644,000.00 ~~114~~122,~~763~~397.9230 0.00 M2 57643LCX2 MEZ 3.~~08250~~33000% 42,653,000.00 ~~116~~122,~~869~~307.2248 0.00 M3 57643LCY0 MEZ 3.~~28250~~53000% 13,065,000.00 3839,~~120~~713.7797 0.00 M4 57643LCZ7 MEZ 3.~~73250~~98000% 11,912,000.00 3940,~~521~~825.3707 0.00 M5 57643LDA1 MEZ 34.~~88250~~13000% 9,222,000.00 3132,~~826~~797.1502 0.00 M6 57643LDB9 MEZ 5.~~18250~~43000% 11,528,000.00 53,~~105~~903.6501 0.00 M7 57643LDC7 MEZ 6.00000% 8,454,000.00 42,270.00 0.00 CE MAB4WM1CE OC 0.00000% 8,069,453.80 21,~~139~~901,~~859~~621.6429 0.00 R MAB4WM1R1 RES 0.00000% 0.00 0.00 0.00 R-X MAB4WM1RX RES 0.00000% 0.00 0.00 0.00 P MAB04WM1P Pre_Pay 0.00000% 100.00 ~~929~~718,~~627~~091.1181 0.00 Totals ~~594~~554,~~123~~894,~~423~~237.9186 43,~~345~~900,~~999~~843.89 3937,~~229~~430,~~186~~926.0596

Certificateholder Distribution Summary (continued) Current Ending Cumulative Realized Certificate Total Realized Class Loss Balance Distribution Losses A1 0.00 ~~157~~137,~~404~~096,~~072~~076.6981 1820,~~802~~633,~~344~~297.7263 0.00 A2 0.00 28,170,000.00 5762,~~905~~099.0020 0.00 A3 0.00 9891,~~366~~472,~~312~~713.3629 97,~~005~~097,~~927~~736.0849 0.00 A4 0.00 166,~~241~~011,~~299~~967.0100 1210,~~014~~261,~~365~~219.8709 0.00 A5 0.00 79,850,000.00 ~~152~~165,~~779~~023.6733 0.00 A6 0.00 17,315,000.00 3538,~~899~~468.7716 0.00 M1 0.00 52,644,000.00 ~~114~~122,~~763~~397.9230 0.00 M2 0.00 42,653,000.00 ~~116~~122,~~869~~307.2248 0.00 M3 0.00 13,065,000.00 3839,~~120~~713.7797 0.00 M4 0.00 11,912,000.00 3940,~~521~~825.3707 0.00 M5 0.00 9,222,000.00 3132,~~826~~797.1502 0.00 M6 0.00 11,528,000.00 53,~~105~~903.6501 0.00 M7 0.00 8,454,000.00 42,270.00 0.00 CE 0.00 8,069,453.80 21,~~139~~901,~~859~~621.6429 0.00 R 0.00 0.00 0.00 0.00 R-X 0.00 0.00 0.00 0.00 P 0.00 100.00 ~~929~~718,~~627~~091.1181 0.00 Totals 0.00 ~~554~~517,~~894~~463,~~237~~310.8690 4341,~~575~~331,~~185~~770.9485 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) A1 253,534,000.00 ~~175~~157,~~869~~404,~~919~~072.6369 0.00 1820,~~465~~307,~~846~~995.9488 0.00 0.00 A2 28,170,000.00 28,170,000.00 0.00 0.00 0.00 0.00 A3 151,682,000.00 ~~107~~98,~~166~~366,~~242~~312.1136 0.00 86,~~799~~893,~~929~~599.7507 0.00 0.00 A4 80,421,000.00 2816,~~204~~241,~~708~~299.3701 0.00 1110,~~963~~229,~~409~~332.3601 0.00 0.00 A5 79,850,000.00 79,850,000.00 0.00 0.00 0.00 0.00 A6 17,315,000.00 17,315,000.00 0.00 0.00 0.00 0.00 M1 52,644,000.00 52,644,000.00 0.00 0.00 0.00 0.00 M2 42,653,000.00 42,653,000.00 0.00 0.00 0.00 0.00 M3 13,065,000.00 13,065,000.00 0.00 0.00 0.00 0.00 M4 11,912,000.00 11,912,000.00 0.00 0.00 0.00 0.00 M5 9,222,000.00 9,222,000.00 0.00 0.00 0.00 0.00 M6 11,528,000.00 11,528,000.00 0.00 0.00 0.00 0.00 M7 8,454,000.00 8,454,000.00 0.00 0.00 0.00 0.00 CE 8,069,309.07 8,069,453.80 0.00 0.00 0.00 0.00 R 0.00 0.00 0.00 0.00 0.00 0.00 R-X 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 768,519,409.07 ~~594~~554,~~123~~894,~~423~~237.9186 0.00 3937,~~229~~430,~~186~~926.0596 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 A1 1820,~~465~~307,~~846~~995.9488 ~~157~~137,~~404~~096,~~072~~076.6981 0.~~62084010~~54074040 1820,~~465~~307,~~846~~995.9488 A2 0.00 28,170,000.00 1.00000000 0.00 A3 86,~~799~~893,~~929~~599.7507 9891,~~366~~472,~~312~~713.3629 0.~~64850353~~60305582 86,~~799~~893,~~929~~599.7507 A4 1110,~~963~~229,~~409~~332.3601 166,~~241~~011,~~299~~967.0100 0.~~20195346~~07475618 1110,~~963~~229,~~409~~332.3601 A5 0.00 79,850,000.00 1.00000000 0.00 A6 0.00 17,315,000.00 1.00000000 0.00 M1 0.00 52,644,000.00 1.00000000 0.00 M2 0.00 42,653,000.00 1.00000000 0.00 M3 0.00 13,065,000.00 1.00000000 0.00 M4 0.00 11,912,000.00 1.00000000 0.00 M5 0.00 9,222,000.00 1.00000000 0.00 M6 0.00 11,528,000.00 1.00000000 0.00 M7 0.00 8,454,000.00 1.00000000 0.00 CE 0.00 8,069,453.80 1.00001794 0.00 R 0.00 0.00 0.00000000 0.00 R-X 0.00 0.00 0.00000000 0.00 P 0.00 100.00 1.00000000 0.00 Totals 3937,~~229~~430,~~186~~926.0596 ~~554~~517,~~894~~463,~~237~~310.8690 0.~~72203022~~67332497 3937,~~229~~430,~~186~~926.0596

Principal Distribution Factors Statement Original Beginning Scheduled Unscheduled Face Certificate Principal Principal Class (2) Amount Balance Distribution Distribution Accretion A1 253,534,000.00 ~~693~~620.~~67390421~~84009517 0.00000000 7280.~~83380904~~09969424 0.00000000 A2 28,170,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 A3 151,682,000.00 ~~706~~648.~~51917901~~50352949 0.00000000 5845.~~01564952~~44770685 0.00000000 A4 80,421,000.00 ~~350~~201.~~71322627~~95345755 0.00000000 ~~148~~127.~~75976872~~19727447 0.00000000 A5 79,850,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 A6 17,315,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M1 52,644,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M2 42,653,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M3 13,065,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M4 11,912,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M5 9,222,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M6 11,528,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 M7 8,454,000.00 1000.00000000 0.00000000 0.00000000 0.00000000 CE 8,069,309.07 1000.01793586 0.00000000 0.00000000 0.00000000 R 0.00 0.00000000 0.00000000 0.00000000 0.00000000 R-X 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 A1 0.00000000 7280.~~83380904~~09969424 ~~620~~540.~~84009517~~74040093 0.~~62084010~~54074040 7280.~~83380904~~09969424 A2 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 A3 0.00000000 5845.~~01564952~~44770685 ~~648~~603.~~50352949~~05582264 0.~~64850353~~60305582 5845.~~01564952~~44770685 A4 0.00000000 ~~148~~127.~~75976872~~19727447 ~~201~~74.~~95345755~~75618309 0.~~20195346~~07475618 ~~148~~127.~~75976872~~19727447 A5 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 A6 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M1 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M2 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M3 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M4 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M5 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M6 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 M7 0.00000000 0.00000000 1,000.00000000 1.00000000 0.00000000 CE 0.00000000 0.00000000 1,000.01793586 1.00001794 0.00000000 R 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 R-X 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, Bankruptcy, 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 A1 253,534,000.00 2.~~15250~~40000% ~~175~~157,~~869~~404,~~919~~072.6369 ~~336~~325,~~497~~301.7875 0.00 0.00 A2 28,170,000.00 2.~~31250~~56000% 28,170,000.00 5762,~~905~~099.0020 0.00 0.00 A3 151,682,000.00 2.~~16250~~41000% ~~107~~98,~~166~~366,~~242~~312.1136 ~~205~~204,~~997~~137.3342 0.00 0.00 A4 80,421,000.00 2.~~03250~~28000% 2816,~~204~~241,~~708~~299.3701 5031,~~956~~887.5108 0.00 0.00 A5 79,850,000.00 2.~~15250~~40000% 79,850,000.00 ~~152~~165,~~779~~023.6733 0.00 0.00 A6 17,315,000.00 2.~~33250~~58000% 17,315,000.00 3538,~~899~~468.7716 0.00 0.00 M1 52,644,000.00 2.~~45250~~70000% 52,644,000.00 ~~114~~122,~~763~~397.9230 0.00 0.00 M2 42,653,000.00 3.~~08250~~33000% 42,653,000.00 ~~116~~122,~~869~~307.2248 0.00 0.00 M3 13,065,000.00 3.~~28250~~53000% 13,065,000.00 3839,~~120~~713.7797 0.00 0.00 M4 11,912,000.00 3.~~73250~~98000% 11,912,000.00 3940,~~521~~825.3707 0.00 0.00 M5 9,222,000.00 34.~~88250~~13000% 9,222,000.00 3132,~~826~~797.1502 0.00 0.00 M6 11,528,000.00 5.~~18250~~43000% 11,528,000.00 53,~~105~~903.6501 0.00 0.00 M7 8,454,000.00 6.00000% 8,454,000.00 42,270.00 0.00 0.00 CE 8,069,309.07 0.00000% 8,069,453.80 0.00 0.00 0.00 R 0.00 0.00000% 0.00 0.00 0.00 0.00 R-X 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 768,519,409.07 1,~~276~~281,~~513~~130.1479 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 A1 0.00 0.00 ~~336~~325,~~497~~301.7875 0.00 ~~157~~137,~~404~~096,~~072~~076.6981 A2 0.00 0.00 5762,~~905~~099.0020 0.00 28,170,000.00 A3 0.00 0.00 ~~205~~204,~~997~~137.3342 0.00 9891,~~366~~472,~~312~~713.3629 A4 0.00 0.00 5031,~~956~~887.5108 0.00 166,~~241~~011,~~299~~967.0100 A5 0.00 0.00 ~~152~~165,~~779~~023.6733 0.00 79,850,000.00 A6 0.00 0.00 3538,~~899~~468.7716 0.00 17,315,000.00 M1 0.00 0.00 ~~114~~122,~~763~~397.9230 0.00 52,644,000.00 M2 0.00 0.00 ~~116~~122,~~869~~307.2248 0.00 42,653,000.00 M3 0.00 0.00 3839,~~120~~713.7797 0.00 13,065,000.00 M4 0.00 0.00 3940,~~521~~825.3707 0.00 11,912,000.00 M5 0.00 0.00 3132,~~826~~797.1502 0.00 9,222,000.00 M6 0.00 0.00 53,~~105~~903.6501 0.00 11,528,000.00 M7 0.00 0.00 42,270.00 0.00 8,454,000.00 CE 0.00 0.00 21,~~139~~901,~~859~~621.6429 0.00 8,069,453.80 R 0.00 0.00 0.00 0.00 0.00 R-X 0.00 0.00 0.00 0.00 0.00 P 0.00 0.00 ~~929~~718,~~627~~091.1181 0.00 100.00 Totals 0.00 0.00 43,~~345~~900,~~999~~843.89 0.00 (4) Amount Does Not Include Excess Special Hazard, Bankruptcy, 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 A1 253,534,000.00 2.~~15250~~40000% ~~693~~620.~~67390421~~84009517 1.~~32722941~~28306953 0.00000000 0.00000000 A2 28,170,000.00 2.~~31250~~56000% 1000.00000000 2.~~05555556~~20444444 0.00000000 0.00000000 A3 151,682,000.00 2.~~16250~~41000% ~~706~~648.~~51917901~~50352949 1.~~35808685~~34582495 0.00000000 0.00000000 A4 80,421,000.00 2.~~03250~~28000% ~~350~~201.~~71322627~~95345755 0.~~63362194~~39650191 0.00000000 0.00000000 A5 79,850,000.00 2.~~15250~~40000% 1000.00000000 12.~~91333338~~06666662 0.00000000 0.00000000 A6 17,315,000.00 2.~~33250~~58000% 1000.00000000 2.~~07333353~~22166676 0.00000000 0.00000000 M1 52,644,000.00 2.~~45250~~70000% 1000.00000000 2.~~18000000~~32500000 0.00000000 0.00000000 M2 42,653,000.00 3.~~08250~~33000% 1000.00000000 2.~~74000000~~86750006 0.00000000 0.00000000 M3 13,065,000.00 3.~~28250~~53000% 1000.00000000 23.~~91777803~~03972216 0.00000000 0.00000000 M4 11,912,000.00 3.~~73250~~98000% 1000.00000000 3.~~31777787~~42722213 0.00000000 0.00000000 M5 9,222,000.00 34.~~88250~~13000% 1000.00000000 3.~~45111147~~55638907 0.00000000 0.00000000 M6 11,528,000.00 5.~~18250~~43000% 1000.00000000 4.~~60666638~~67583362 0.00000000 0.00000000 M7 8,454,000.00 6.00000% 1000.00000000 5.00000000 0.00000000 0.00000000 CE 8,069,309.07 0.00000% 1000.01793586 0.00000000 0.00000000 0.00000000 R 0.00 0.00000% 0.00000000 0.00000000 0.00000000 0.00000000 R-X 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 A1 0.00000000 0.00000000 1.~~32722941~~28306953 0.00000000 ~~620~~540.~~84009517~~74040093 A2 0.00000000 0.00000000 2.~~05555556~~20444444 0.00000000 1000.00000000 A3 0.00000000 0.00000000 1.~~35808685~~34582495 0.00000000 ~~648~~603.~~50352949~~05582264 A4 0.00000000 0.00000000 0.~~63362194~~39650191 0.00000000 ~~201~~74.~~95345755~~75618309 A5 0.00000000 0.00000000 12.~~91333338~~06666662 0.00000000 1000.00000000 A6 0.00000000 0.00000000 2.~~07333353~~22166676 0.00000000 1000.00000000 M1 0.00000000 0.00000000 2.~~18000000~~32500000 0.00000000 1000.00000000 M2 0.00000000 0.00000000 2.~~74000000~~86750006 0.00000000 1000.00000000 M3 0.00000000 0.00000000 23.~~91777803~~03972216 0.00000000 1000.00000000 M4 0.00000000 0.00000000 3.~~31777787~~42722213 0.00000000 1000.00000000 M5 0.00000000 0.00000000 3.~~45111147~~55638907 0.00000000 1000.00000000 M6 0.00000000 0.00000000 4.~~60666638~~67583362 0.00000000 1000.00000000 M7 0.00000000 0.00000000 5.00000000 0.00000000 1000.00000000 CE 0.00000000 0.00000000 ~~265~~235.~~18498938~~66098082 0.00000000 1000.01793586 R 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 R-X 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 P 0.00000000 0.00000000 ~~9296271~~7180918.10000000 0.00000000 1000.00000000 (6) Amount Does Not Include Excess Special Hazard, Bankruptcy,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 4240,~~895~~847,~~585~~197.7510 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 ~~929~~718,~~627~~091.1181 Total Deposits 4341,~~825~~565,~~212~~288.8691 Withdrawals Reimbursement for Servicer Advances 0.00 Payment of Service Fee ~~250~~233,~~026~~518.9306 Payment of Interest and Principal 4341,~~575~~331,~~185~~770.9385 Total Withdrawals (Pool Distribution Amount) 4341,~~825~~565,~~212~~288.8691 Ending Balance 0.00

SERVICING FEES Gross Servicing Fee ~~247~~231,~~551~~205.4297 Administrator fee 2,~~475~~312.5109 Supported Prepayment/Curtailment Interest Shortfall 0.00 Net Servicing Fee ~~250~~233,~~026~~518.9306

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 22 1 0 23 2,~~342~~359,~~268~~619.2103 113,~~833~~744.7992 0.00 2,~~456~~473,~~102~~363.0095 30 Days 6656 02 17 0 6765 118,~~391~~655,~~375~~923.0468 0135,524.00 ~~202~~970,~~855~~720.7389 0.00 119,~~594~~762,~~230~~168.7757 60 Days 1914 32 6 0 2822 31,~~797~~927,~~095~~156.6861 ~~367~~267,~~672~~709.5612 ~~948~~771,~~893~~118.4087 0.00 52,~~113~~965,~~661~~984.6460 90 Days 6 03 1210 0 1819 ~~631~~1,~~272~~193,191.1713 0292,237.0031 21,~~101~~392,~~080~~196.6784 0.00 2,~~732~~877,~~352~~625.8428 120 Days 0 2 5 1 811 0 14 218,120.0011 ~~539~~71,~~989~~703.64 1,~~110~~879,~~563~~194.7881 ~~55,415~~0.6500 12,~~705~~169,~~969~~018.0756 150 Days 0 3 24 91 8 0.00 ~~14 298~~1,~~478~~021,224.3366 ~~239~~629,~~458~~328.4876 255,~~542,221~~415.2065 ~~0.00 3~~1,~~080~~705,~~158~~969.0107 180+ Days 7 5 615 810 937 ~~28 322~~590,~~165~~071.6536 ~~495~~513,~~377~~296.9289 13,~~284~~555,~~484~~747.1927 1,~~223~~315,~~238~~840.9410 35,~~325~~974,~~266~~955.7062 Totals 9985 3538 4254 1011 ~~186~~188 1612,~~440~~584,~~386~~462.8789 34,~~984~~661,~~766~~314.8165 89,~~303~~312,~~932~~052.7636 1,~~278~~371,~~654~~255.5975 3027,~~007~~929,~~741~~085.0365 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.~~613839~~654957% 0.~~027902~~029771% 0.000000% 0.~~641741~~684728% 0.~~421734~~455583% 0.~~020496~~021961% 0.000000% 0.~~442231~~477544% 30 Days 1.~~841518~~667163% 0.~~000000~~059542% 0.~~027902~~208395% 0.000000% 1.~~869420~~935100% 21.~~051061~~671241% 0.~~000000~~026166% 0.~~036525~~187422% 0.000000% 21.~~087586~~884830% 60 Days 0.~~530134~~416791% 0.~~083705~~059542% 0.~~167411~~178625% 0.000000% 0.~~781250~~654957% 0.~~683682~~372086% 0.~~066201~~051688% 0.~~170852~~148884% 0.000000% 0.~~920735~~572657% 90 Days 0.~~167411~~178625% 0.~~000000~~089312% 0.~~334821~~297708% 0.000000% 0.~~502232~~565645% 0.~~113663~~230375% 0.~~000000~~056424% 0.~~378308~~268798% 0.000000% 0.~~491971~~555597% 120 Days 0.~~000000~~059542% 0.~~055804~~029771% 0.~~139509~~327478% 0.~~027902~~000000% 0.~~223214~~416791% 0.~~000000~~042114% 0.~~097227~~013844% 0.~~199961~~362825% 0.~~009978~~000000% 0.~~307166~~418783% 150 Days 0.~~083705~~000000% 0.~~055804~~089312% 0.~~251116~~119083% 0.~~000000~~029771% 0.~~390625~~238166% 0.~~053742~~000000% 0.~~043115~~197173% 0.~~457737~~121508% 0.~~000000~~010699% 0.~~554594~~329380% 180+ Days 0.~~139509~~208395% 0.~~167411~~148854% 0.~~223214~~446561% 0.~~251116~~297708% 01.~~781250~~101518% 0.~~058007~~113928% 0.~~089195~~099105% 0.~~231276~~686525% 0.~~220249~~254056% 01.~~598727~~153614% Totals 2.~~762277~~530515% 01.~~976563~~131289% 1.~~171875~~607621% 0.~~279018~~327478% 5.~~189732~~596904% 2.~~960155~~429744% 0.~~717473~~899983% 1.~~495155~~797923% 0.~~230227~~264755% 5.~~403010~~392405% (7) Delinquencies are stratified according to the information the Servicer has provided.

OTHER INFORMATION Current Period Class A Insufficient Funds 0.00 Principal Balance of Contaminated Properties 0.00 Periodic Advance ~~194~~183,~~376~~047.0204 Class A-6 157,547,309.07 20.50010803% 157,547,453.80 2830.~~39233913~~44611096% 3.~~120414~~346131% 0.000000% Class M-1 104,903,309.07 13.65005331% 104,903,453.80 1820.~~90512581~~27263607% 910.~~487213~~173475% 0.000000% Class M-2 62,250,309.07 8.10003083% 62,250,453.80 1112.~~21843579~~02992608% 78.~~686690~~242710% 0.000000% Class M-3 49,185,309.07 6.40000870% 49,185,453.80 89.~~86393306~~50510940% 2.~~354503~~524817% 0.000000% Class M-4 37,273,309.07 4.85001532% 37,273,453.80 67.~~71721767~~20311045% 2.~~146715~~301999% 0.000000% Class CE 0.00 0.00000000% 0.00 0.00000000% 1.~~454233~~559425% 0.000000% Class R-I 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.~~409308~~402122% Weighted Average Net Coupon 6.~~909308~~902122% Weighted Average Pass-Through Rate 6.~~904308~~897122% Weighted Average Maturity(Stepdown Calculation ) ~~329~~328 Beginning Scheduled Collateral Loan Count 3,~~816~~584 Number Of Loans Paid In Full ~~232~~225 Ending Scheduled Collateral Loan Count 3,~~584~~359 Beginning Scheduled Collateral Balance ~~594~~554,~~123~~894,~~423~~237.9085 Ending Scheduled Collateral Balance ~~554~~517,~~894~~463,~~237~~310.8589 Ending Actual Collateral Balance at 3130-~~Oct~~Nov-2004 ~~555~~517,~~389~~933,~~341~~774.9216 Monthly P &I Constant 43,~~148~~876,~~883~~605.8245 Special Servicing Fee 0.00 Prepayment Penalties ~~929~~718,~~627~~091.1181 Realized Loss Amount 0.00 Cumulative Realized Loss 936.10 Ending Scheduled Balance for Premium Loans ~~554~~517,~~894~~463,~~237~~310.8589 Scheduled Principal ~~480~~453,~~514~~776.5045 Unscheduled Principal 3836,~~748~~977,~~671~~150.5551

Other Income (16,~~969~~558.6293)

Miscellaneous Reporting Net Monthly Excess Cashflow 21,~~139~~901,~~859~~621.8028 Extra Prinicpal Distribution Amount 0.00 OC Amount 8,069,453.80 OC Deficiency Amount 0.00 OC Release Amount 0.00 OC Target Amount 8,069,453.7980 Stepdown 0.00 Trigger Event 0.00 Credit Enhancement Percentage 2630.~~517630422~~446111%

Group Level Collateral Statement Group Group 1 Group 2 Group 3 Collateral Description Fixed 15/30 & ARM Fixed 15/30 & ARM Fixed 15/30 & ARM Weighted Average Coupon Rate 8.~~163898~~133284 7.~~189048~~198862 8.~~183719~~148485 Weighted Average Net Rate 7.~~663898~~633284 6.~~689048~~698862 7.~~683719~~648485 Weighted Average Maturity ~~286~~285 ~~348~~347 ~~288~~287 Beginning Loan Count ~~911~~862 1,~~208~~137 ~~470~~444 Loans Paid In Full 4950 7186 2620 Ending Loan Count ~~862~~812 1,~~137~~051 ~~444~~424 Beginning Scheduled Balance 7571,~~462~~388,~~792~~220.6772 ~~201~~186,~~066~~675,~~291~~016.6162 4038,~~484~~676,~~768~~175.5882 Ending scheduled Balance 7167,~~388~~645,~~220~~432.7233 ~~186~~170,~~675~~109,~~016~~809.6213 3837,~~676~~345,~~175~~254.8277 Record Date 1011/3130/2004 1011/3130/2004 1011/3130/2004 Principal And Interest Constant ~~582~~550,~~700~~929.1078 1,~~366~~270,~~568~~897.3395 ~~313~~298,~~110~~357.0343 Scheduled Principal 6967,~~308~~079.0123 ~~162~~151,~~005~~024.6095 3735,~~013~~730.3957 Unscheduled Principal 43,~~005~~675,~~263~~709.9416 1416,~~229~~414,~~269~~182.3954 1,~~771~~295,~~579~~190.3748 Scheduled Interest ~~513~~483,~~392~~850.0955 1,~~204~~119,~~562~~873.7300 ~~276~~262,~~096~~626.6486 Servicing Fees 3129,~~442~~745.8310 8377,~~777~~781.6225 16,~~868~~115.6508 Master Servicing Fees 0.00 0.00 0.00 Trustee Fee 0.00 0.00 0.00 FRY Amount 0.00 0.00 0.00 Special Hazard Fee 0.00 0.00 0.00 Other Fee ~~314~~297.4246 ~~837~~777.7684 ~~168~~161.6914 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 ~~481~~453,~~634~~807.8499 1,~~119~~041,~~947~~313.3591 ~~259~~246,~~059~~350.3064 Realized Loss Amount 0.00 0.00 0.00 Cumulative Realized Loss 0.00 0.00 0.00 Percentage of Cumulative Losses 0.0000 0.0000 0.0000 Prepayment Penalties 0.00 0.00 0.00 Special Servicing Fee 0.00 0.00 0.00 Pass-Through Rate 7.~~658898~~628284 6.~~684048~~693862 7.~~678719~~643485

Group Level Collateral Statement Group Group 4 Group 5 Group 6 Collateral Description Fixed 15/30 & ARM Fixed 15/30 & ARM Fixed 15/30 & ARM Weighted Average Coupon Rate 7.~~178803~~189543 8.~~559798~~463658 6.~~806635~~800189 Weighted Average Net Rate 6.~~678804~~689543 87.~~059798~~963658 6.~~306635~~300189 Weighted Average Maturity ~~348~~347 ~~247~~246 ~~348~~347 Beginning Loan Count ~~619~~586 ~~317~~285 ~~291~~270 Loans Paid In Full 3328 3223 2118 Ending Loan Count ~~586~~558 ~~285~~262 ~~270~~252 Beginning Scheduled Balance ~~105~~98,~~706~~714,~~118~~781.6869 4744,~~717~~387,~~896~~743.8507 ~~123~~115,~~685~~052,~~555~~299.5193 Ending scheduled Balance 9893,~~714~~152,~~781~~103.6967 4441,~~387~~875,~~743~~543.0773 ~~115~~107,~~052~~335,~~299~~167.9326 Record Date 1011/3130/2004 1011/3130/2004 1011/3130/2004 Principal And Interest Constant ~~718~~671,~~083~~793.7563 ~~374~~345,~~676~~866.8647 ~~793~~738,~~744~~760.7519 Scheduled Principal 8580,~~714~~365.2113 3432,~~297~~797.2257 9286,~~176~~779.0700 Unscheduled Principal 65,~~905~~482,~~622~~312.7889 32,~~295~~479,~~856~~401.5677 87,~~541~~630,~~079~~353.5167 Scheduled Interest ~~632~~591,~~369~~428.5450 ~~340~~313,~~379~~068.6490 ~~701~~651,~~568~~981.6819 Servicing Fees 4441,~~044~~131.21 19 18,~~882~~494.4588 5147,~~535~~938.6647 Master Servicing Fees 0.00 0.00 0.00 Trustee Fee 0.00 0.00 0.00 FRY Amount 0.00 0.00 0.00 Special Hazard Fee 0.00 0.00 0.00 Other Fee ~~440~~411.4433 ~~198~~184.8395 ~~515~~479.37 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 ~~587~~549,~~884~~885.8998 ~~320~~294,~~298~~389.3607 ~~649~~603,~~517~~563.6535 Realized Loss Amount 0.00 0.00 0.00 Cumulative Realized Loss 0.00 0.00 936.10 Percentage of Cumulative Losses 0.0000 0.0000 0.0006 Prepayment Penalties 0.00 0.00 0.00 Special Servicing Fee 0.00 0.00 0.00 Pass-Through Rate 6.~~673803~~684543 87.~~054798~~958658 6.~~301635~~295189

Group Level Collateral Statement Group Total Collateral Description Mixed Fixed & Arm Weighted Average Coupon Rate 7.~~409308~~402122 Weighted Average Net Rate 6.~~909308~~902122 Weighted Average Maturity ~~329~~328.00 Record Date 1011/3130/2004 Principal And Interest Constant 43,~~148~~876,~~883~~605.8245 Beginning Loan Count 3,~~816~~584 Loans Paid In Full ~~232~~225 Ending Loan Count 3,~~584~~359 Beginning Scheduled Balance ~~594~~554,~~123~~894,~~423~~237.9085 Ending Scheduled Balance ~~554~~517,~~894~~463,~~237~~310.8589 Scheduled Principal ~~480~~453,~~514~~776.5045 Unscheduled Principal 3836,~~748~~977,~~671~~150.5551 Scheduled Interest 3,~~668~~422,~~369~~829.3200 Servicing Fee ~~247~~231,~~551~~205.4297 Master Servicing Fee 0.00 Trustee Fee 0.00 Fry Amount 0.00 Special Hazard Fee 0.00 Other Fee 2,~~475~~312.5109 Pool Insurance Fee 0.00 Spread 1 0.00 Spread 2 0.00 Spread 3 0.00 Net Interest 3,~~418~~189,~~342~~310.3994 Realized Loss Amount 0.00 Cumulative Realized Loss 936.10 Percentage of Cumulative Losses 0.0001 Prepayment Penalties 0.00 Special Servicing Fee 0.00 Pass-Through Rate 6.~~904308~~897122

Filing Compare · MORTGAGE ASSET SEC TRANS INC MASTR AS BK SEC TR 2004 WMC1