WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Class	Cusip	Orig Prin Bal	Begin Prin Bal	Int Rate Accrued	Int Rate Paid	Int Dist	Prin Dist	Int Shortfall	Prin Loss	Deferred Interest	Int Reimbursed	Unscheduled Int	Prin Reimbursed	Subsequent Recoveries	Total Dist	Ending Class Bal
IA1	939335B20	$35,000,000.00	$0.05	6.5000000000%	6.5000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.05
IA2	939335B38	$29,706,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA3	939335B46	$3,000,000.00	$860,103.24	6.7500000000%	6.7500000000%	$4,838.08	$860,103.24	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$864,941.32	$0.00
IA4	939335B53	$33,693,117.00	$33,693,117.00	6.5000000000%	6.5000000000%	$182,504.38	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$182,504.38	$33,693,117.00
IA5	939335B61	$2,000,000.00	$2,000,000.00	6.7500000000%	6.7500000000%	$11,250.00	$2,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$2,011,250.00	$0.00
IA6	939335B79	$2,475,000.00	$2,475,000.00	6.7500000000%	6.7500000000%	$13,921.88	$979,096.35	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$993,018.23	$1,495,903.65
IA7	939335B87	$2,525,000.00	$2,525,000.00	6.7500000000%	6.7500000000%	$14,203.13	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$14,203.13	$2,525,000.00
IA8	939335B95	$3,000,000.00	$3,000,000.00	6.7500000000%	6.7500000000%	$16,875.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$16,875.00	$3,000,000.00
IA9	939335C29	$607,693.00	$525,389.18	0.0000000000%	0.0000000000%	$0.00	$147,661.69	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$147,661.69	$377,727.49
IA10	939335C37	$2,800,000.00	$2,800,000.00	6.7500000000%	6.7500000000%	$15,750.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$15,750.00	$2,800,000.00
IA11	939335C45	$100,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA12	939335C52	$11,142,877.00	$4,788,234.94	6.5000000000%	6.5000000000%	$25,936.27	$1,345,743.07	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,371,679.35	$3,442,491.87
IA13	939335C60	$25,000,000.00	$4,252,825.40	6.5000000000%	6.5000000000%	$23,036.14	$492,620.20	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$515,656.33	$3,760,205.20
IA14	939335C78	$89,762,051.00	$0.13	6.2500000000%	6.2500000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.13
IA15	939335C86	$11,220,256.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA16	939335C94	$11,220,256.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA17	939335D28	$2,400,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA18	939335D36	$2,500,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA19	939335D44	$2,400,000.00	$1,026,838.89	6.5000000000%	6.5000000000%	$5,562.04	$1,026,838.89	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,032,400.93	$0.00
IA20	939335D51	$2,000,000.00	$2,000,000.00	6.5000000000%	6.5000000000%	$10,833.33	$301,648.70	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$312,482.03	$1,698,351.30
IA21	939335D69	$1,700,000.00	$1,700,000.00	6.5000000000%	6.5000000000%	$9,208.33	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$9,208.33	$1,700,000.00
IA22	939335D77	$112,000.00	$112,000.00	6.5000000000%	6.5000000000%	$606.67	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$606.67	$112,000.00
IIA1	939335D85	$100,500,000.00	$18,568,215.73	6.2500000000%	6.2500000000%	$96,709.46	$1,410,588.56	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,507,298.02	$17,157,627.17
IIA2	939335D93	$41,400,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA3	939335E27	$5,200,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA4	939335E35	$18,858,451.00	$18,858,451.00	6.2500000000%	6.2500000000%	$98,221.10	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$98,221.10	$18,858,451.00
IIA5	939335E43	$41,400,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA6	939335E50	$50,733,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA7	939335E68	$5,754,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA8	939335E76	$10,240,000.00	$9,359,872.06	6.2500000000%	6.2500000000%	$48,749.33	$1,549,954.48	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,598,703.82	$7,809,917.58
IIA9	939335E84	$15,000,000.00	$6,624,425.82	6.2500000000%	6.2500000000%	$34,502.22	$1,096,976.37	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,131,478.59	$5,527,449.45

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Class	Cusip	Orig Prin Bal	Begin Prin Bal	Int Rate Accrued	Int Rate Paid	Int Dist	Prin Dist	Int Shortfall	Prin Loss	Deferred Interest	Int Reimbursed	Unscheduled Int	Prin Reimbursed	Subsequent Recoveries	Total Dist	Ending Class Bal
IIIA1	939335E92	$87,377,000.00	$10,333,497.67	5.5000000000%	5.5000000000%	$47,361.86	$6,116,962.80	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$6,164,324.66	$4,216,534.87
IIIA2	939335F26	$10,485,240.00	$1,240,019.72	6.2500000000%	6.2500000000%	$6,458.44	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$6,458.44	$505,984.18
IIIA3	939335F34	$4,610,000.00	$4,610,000.00	6.2500000000%	6.2500000000%	$24,010.42	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$24,010.42	$4,610,000.00
IIIA4	939335F42	$18,686,107.00	$18,686,107.00	6.2500000000%	6.2500000000%	$97,323.47	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$97,323.47	$18,686,107.00
IIIA5	939335F59	$2,969,080.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA6	939335F67	$2,995,920.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA7	939335F75	$34,468,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA8	939335F83	$13,647,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA9	939335F91	$21,761,187.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA10	939335G25	$5,021,813.00	$0.01	23.0750000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.01
IIIA11	939335G33	$520,000.00	$520,000.00	6.2500000000%	6.2500000000%	$2,708.33	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$2,708.33	$520,000.00
CX	939335G41	$6,399,262.00	$865,480.20	6.2500000000%	6.2499999764%	$4,507.71	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$4,507.71	$616,409.24
CP	939335G58	$3,597,122.00	$1,643,226.89	0.0000000000%	0.0000000000%	$0.00	$108,035.26	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$108,035.26	$1,535,191.63
CB1	939335G66	$14,012,936.00	$13,752,442.79	6.3575215508%	6.3575215508%	$72,859.54	$14,227.23	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$87,086.77	$13,738,215.56
CB2	939335G74	$5,254,853.00	$5,157,168.02	6.3575215508%	6.3575215508%	$27,322.34	$5,335.21	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$32,657.55	$5,151,832.81
CB3	939335G82	$3,503,233.00	$3,438,109.72	6.3575215508%	6.3575215508%	$18,214.88	$3,556.81	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$21,771.69	$3,434,552.91
CB4	939335A70	$1,751,618.00	$1,719,056.34	6.3575215508%	6.3575215508%	$9,107.45	$1,778.40	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$10,885.85	$1,717,277.94
CB5	939335A88	$1,751,617.00	$1,719,055.35	6.3575215508%	6.3575215508%	$9,107.44	$1,778.40	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$10,885.85	$1,717,276.95
CB6	939335A96	$1,751,618.00	$1,719,057.13	6.3575215508%	6.3575215508%	$9,107.45	$1,778.40	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$10,885.86	$1,717,278.73
R	939335G90	$50.00	$0.00	0.0000000000%	0.0000000000%	$0.01	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.01	$0.00
R_SYN	XXXXXXXXX	$0.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
Total		$875,808,599.00	$178,467,194.36			$940,796.71	$17,464,684.08	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$18,405,480.79	$161,002,510.28

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Class	Orig Face	Beg Bal	Prin Loss	Prin Reimbursed	Subsequent Recoveries	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IA1	$35,000,000.00	$0.05	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000014	$0.05
IA2	$29,706,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA3	$3,000,000.00	$860,103.24	$0.00	$0.00	$0.00	$0.00	$860,103.24	0.0000000000	$0.00
IA4	$33,693,117.00	$33,693,117.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$33,693,117.00
IA5	$2,000,000.00	$2,000,000.00	$0.00	$0.00	$0.00	$0.00	$2,000,000.00	0.0000000000	$0.00
IA6	$2,475,000.00	$2,475,000.00	$0.00	$0.00	$0.00	$0.00	$979,096.35	0.6044055152	$1,495,903.65
IA7	$2,525,000.00	$2,525,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$2,525,000.00
IA8	$3,000,000.00	$3,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$3,000,000.00
IA9	$607,693.00	$525,389.18	$0.00	$0.00	$0.00	$0.00	$147,661.69	0.6215761742	$377,727.49
IA10	$2,800,000.00	$2,800,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$2,800,000.00
IA11	$100,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA12	$11,142,877.00	$4,788,234.94	$0.00	$0.00	$0.00	$0.00	$1,345,743.07	0.3089410275	$3,442,491.87
IA13	$25,000,000.00	$4,252,825.40	$0.00	$0.00	$0.00	$0.00	$492,620.20	0.1504082080	$3,760,205.20
IA14	$89,762,051.00	$0.13	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000014	$0.13
IA15	$11,220,256.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA16	$11,220,256.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA17	$2,400,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA18	$2,500,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA19	$2,400,000.00	$1,026,838.89	$0.00	$0.00	$0.00	$0.00	$1,026,838.89	0.0000000000	$0.00
IA20	$2,000,000.00	$2,000,000.00	$0.00	$0.00	$0.00	$0.00	$301,648.70	0.8491756500	$1,698,351.30
IA21	$1,700,000.00	$1,700,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$1,700,000.00
IA22	$112,000.00	$112,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$112,000.00
IIA1	$100,500,000.00	$18,568,215.73	$0.00	$0.00	$0.00	$0.00	$1,410,588.56	0.1707226584	$17,157,627.17
IIA2	$41,400,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA3	$5,200,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA4	$18,858,451.00	$18,858,451.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$18,858,451.00
IIA5	$41,400,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA6	$50,733,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA7	$5,754,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA8	$10,240,000.00	$9,359,872.06	$0.00	$0.00	$0.00	$0.00	$1,549,954.48	0.7626872637	$7,809,917.58
IIA9	$15,000,000.00	$6,624,425.82	$0.00	$0.00	$0.00	$0.00	$1,096,976.37	0.3684966300	$5,527,449.45

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Class	Orig Face	Beg Bal	Prin Loss	Prin Reimbursed	Subsequent Recoveries	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IIIA1	$87,377,000.00	$10,333,497.67	$0.00	$0.00	$0.00	$0.00	$6,116,962.80	0.0482568052	$4,216,534.87
IIIA2	$10,485,240.00	$1,240,019.72	$0.00	$0.00	$0.00	$0.00	$0.00	0.0482568048	$505,984.18
IIIA3	$4,610,000.00	$4,610,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$4,610,000.00
IIIA4	$18,686,107.00	$18,686,107.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$18,686,107.00
IIIA5	$2,969,080.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIIA6	$2,995,920.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIIA7	$34,468,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIIA8	$13,647,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIIA9	$21,761,187.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIIA10	$5,021,813.00	$0.01	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000020	$0.01
IIIA11	$520,000.00	$520,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$520,000.00
CX	$6,399,262.00	$865,480.20	$0.00	$0.00	$0.00	$0.00	$0.00	0.0963250512	$616,409.24
CP	$3,597,122.00	$1,643,226.89	$0.00	$0.00	$0.00	$0.00	$108,035.26	0.4267833090	$1,535,191.63
CB1	$14,012,936.00	$13,752,442.79	$0.00	$0.00	$0.00	$0.00	$14,227.23	0.9803952262	$13,738,215.56
CB2	$5,254,853.00	$5,157,168.02	$0.00	$0.00	$0.00	$0.00	$5,335.21	0.9803952289	$5,151,832.81
CB3	$3,503,233.00	$3,438,109.72	$0.00	$0.00	$0.00	$0.00	$3,556.81	0.9803952264	$3,434,552.91
CB4	$1,751,618.00	$1,719,056.34	$0.00	$0.00	$0.00	$0.00	$1,778.40	0.9803952346	$1,717,277.94
CB5	$1,751,617.00	$1,719,055.35	$0.00	$0.00	$0.00	$0.00	$1,778.40	0.9803952291	$1,717,276.95
CB6	$1,751,618.00	$1,719,057.13	$0.00	$0.00	$0.00	$0.00	$1,778.40	0.9803956856	$1,717,278.73
R	$50.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
R_SYN	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
Total	$875,808,599.00	$178,467,194.36	$0.00	$0.00	$0.00	$0.00	$17,464,684.08	0.1838329864	$161,002,510.28

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003
PER $1000 DENOMINATION
Class	Orig Face	Beg Bal	Prin Loss	Prin Reimbursed	Subsequent Recoveries	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IA1	$35,000,000.00	0.00000143	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000014	0.00000143
IA2	$29,706,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA3	$3,000,000.00	286.70108000	0.00000000	0.00000000	0.00000000	0.00000000	286.70108000	0.0000000000	0.00000000
IA4	$33,693,117.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA5	$2,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1000.00000000	0.0000000000	0.00000000
IA6	$2,475,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	395.59448485	0.6044055152	604.40551515
IA7	$2,525,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA8	$3,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA9	$607,693.00	864.56348847	0.00000000	0.00000000	0.00000000	0.00000000	242.98731432	0.6215761742	621.57617415
IA10	$2,800,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA11	$100,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA12	$11,142,877.00	429.71262628	0.00000000	0.00000000	0.00000000	0.00000000	120.77159875	0.3089410275	308.94102753
IA13	$25,000,000.00	170.11301600	0.00000000	0.00000000	0.00000000	0.00000000	19.70480800	0.1504082080	150.40820800
IA14	$89,762,051.00	0.00000145	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000014	0.00000145
IA15	$11,220,256.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA16	$11,220,256.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA17	$2,400,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA18	$2,500,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA19	$2,400,000.00	427.84953750	0.00000000	0.00000000	0.00000000	0.00000000	427.84953750	0.0000000000	0.00000000
IA20	$2,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	150.82435000	0.8491756500	849.17565000
IA21	$1,700,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA22	$112,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IIA1	$100,500,000.00	184.75836547	0.00000000	0.00000000	0.00000000	0.00000000	14.03570706	0.1707226584	170.72265841
IIA2	$41,400,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA3	$5,200,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA4	$18,858,451.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IIA5	$41,400,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA6	$50,733,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA7	$5,754,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA8	$10,240,000.00	914.05000586	0.00000000	0.00000000	0.00000000	0.00000000	151.36274219	0.7626872637	762.68726367
IIA9	$15,000,000.00	441.62838800	0.00000000	0.00000000	0.00000000	0.00000000	73.13175800	0.3684966300	368.49663000

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003
PER $1000 DENOMINATION
Class	Orig Face	Beg Bal	Prin Loss	Prin Reimbursed	Subsequent Recoveries	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IIIA1	$87,377,000.00	118.26336072	0.00000000	0.00000000	0.00000000	0.00000000	70.00655550	0.0482568052	48.25680522
IIIA2	$10,485,240.00	118.26336069	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0482568048	48.25680480
IIIA3	$4,610,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IIIA4	$18,686,107.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IIIA5	$2,969,080.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIIA6	$2,995,920.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIIA7	$34,468,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIIA8	$13,647,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIIA9	$21,761,187.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIIA10	$5,021,813.00	0.00000199	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000020	0.00000199
IIIA11	$520,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
CX	$6,399,262.00	135.24687691	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0963250512	96.32505123
CP	$3,597,122.00	456.81711379	0.00000000	0.00000000	0.00000000	0.00000000	30.03380480	0.4267833090	426.78330899
CB1	$14,012,936.00	981.41051882	0.00000000	0.00000000	0.00000000	0.00000000	1.01529258	0.9803952262	980.39522624
CB2	$5,254,853.00	981.41052090	0.00000000	0.00000000	0.00000000	0.00000000	1.01529196	0.9803952289	980.39522894
CB3	$3,503,233.00	981.41051994	0.00000000	0.00000000	0.00000000	0.00000000	1.01529359	0.9803952264	980.39522635
CB4	$1,751,618.00	981.41052444	0.00000000	0.00000000	0.00000000	0.00000000	1.01528986	0.9803952346	980.39523458
CB5	$1,751,617.00	981.41051954	0.00000000	0.00000000	0.00000000	0.00000000	1.01529044	0.9803952291	980.39522909
CB6	$1,751,618.00	981.41097545	0.00000000	0.00000000	0.00000000	0.00000000	1.01528986	0.9803956856	980.39568559
R	$50.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
R_SYN	$0.00	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IA1	$35,000,000.00	6.5000000000%	6.5000000000%	$0.05	$0.00	$0.00	$0.00	$0.00	$0.00
IA2	$29,706,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA3	$3,000,000.00	6.7500000000%	6.7500000000%	$860,103.24	$4,838.08	$0.00	$0.00	$0.00	$4,838.08
IA4	$33,693,117.00	6.5000000000%	6.5000000000%	$33,693,117.00	$182,504.38	$0.00	$0.00	$0.00	$182,504.38
IA5	$2,000,000.00	6.7500000000%	6.7500000000%	$2,000,000.00	$11,250.00	$0.00	$0.00	$0.00	$11,250.00
IA6	$2,475,000.00	6.7500000000%	6.7500000000%	$2,475,000.00	$13,921.88	$0.00	$0.00	$0.00	$13,921.88
IA7	$2,525,000.00	6.7500000000%	6.7500000000%	$2,525,000.00	$14,203.13	$0.00	$0.00	$0.00	$14,203.13
IA8	$3,000,000.00	6.7500000000%	6.7500000000%	$3,000,000.00	$16,875.00	$0.00	$0.00	$0.00	$16,875.00
IA9	$607,693.00	0.0000000000%	0.0000000000%	$525,389.18	$0.00	$0.00	$0.00	$0.00	$0.00
IA10	$2,800,000.00	6.7500000000%	6.7500000000%	$2,800,000.00	$15,750.00	$0.00	$0.00	$0.00	$15,750.00
IA11	$100,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA12	$11,142,877.00	6.5000000000%	6.5000000000%	$4,788,234.94	$25,936.27	$0.00	$0.00	$0.00	$25,936.27
IA13	$25,000,000.00	6.5000000000%	6.5000000000%	$4,252,825.40	$23,036.14	$0.00	$0.00	$0.00	$23,036.14
IA14	$89,762,051.00	6.2500000000%	6.2500000000%	$0.13	$0.00	$0.00	$0.00	$0.00	$0.00
IA15	$11,220,256.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA16	$11,220,256.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA17	$2,400,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA18	$2,500,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA19	$2,400,000.00	6.5000000000%	6.5000000000%	$1,026,838.89	$5,562.04	$0.00	$0.00	$0.00	$5,562.04
IA20	$2,000,000.00	6.5000000000%	6.5000000000%	$2,000,000.00	$10,833.33	$0.00	$0.00	$0.00	$10,833.33
IA21	$1,700,000.00	6.5000000000%	6.5000000000%	$1,700,000.00	$9,208.33	$0.00	$0.00	$0.00	$9,208.33
IA22	$112,000.00	6.5000000000%	6.5000000000%	$112,000.00	$606.67	$0.00	$0.00	$0.00	$606.67
IIA1	$100,500,000.00	6.2500000000%	6.2500000000%	$18,568,215.73	$96,709.46	$0.00	$0.00	$0.00	$96,709.46
IIA2	$41,400,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA3	$5,200,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA4	$18,858,451.00	6.2500000000%	6.2500000000%	$18,858,451.00	$98,221.10	$0.00	$0.00	$0.00	$98,221.10
IIA5	$41,400,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA6	$50,733,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA7	$5,754,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA8	$10,240,000.00	6.2500000000%	6.2500000000%	$9,359,872.06	$48,749.33	$0.00	$0.00	$0.00	$48,749.33
IIA9	$15,000,000.00	6.2500000000%	6.2500000000%	$6,624,425.82	$34,502.22	$0.00	$0.00	$0.00	$34,502.22

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IIIA1	$87,377,000.00	5.5000000000%	5.5000000000%	$10,333,497.67	$47,361.86	$0.00	$0.00	$0.00	$47,361.86
IIIA2	$10,485,240.00	6.2500000000%	6.2500000000%	$1,240,019.72	$6,458.44	$0.00	$0.00	$0.00	$6,458.44
IIIA3	$4,610,000.00	6.2500000000%	6.2500000000%	$4,610,000.00	$24,010.42	$0.00	$0.00	$0.00	$24,010.42
IIIA4	$18,686,107.00	6.2500000000%	6.2500000000%	$18,686,107.00	$97,323.47	$0.00	$0.00	$0.00	$97,323.47
IIIA5	$2,969,080.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA6	$2,995,920.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA7	$34,468,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA8	$13,647,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA9	$21,761,187.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA10	$5,021,813.00	23.0750000000%	0.0000000000%	$0.01	$0.00	$0.00	$0.00	$0.00	$0.00
IIIA11	$520,000.00	6.2500000000%	6.2500000000%	$520,000.00	$2,708.33	$0.00	$0.00	$0.00	$2,708.33
CX	$6,399,262.00	6.2500000000%	6.2499999764%	$865,480.20	$4,507.71	$0.00	$0.00	$0.00	$4,507.71
CP	$3,597,122.00	0.0000000000%	0.0000000000%	$1,643,226.89	$0.00	$0.00	$0.00	$0.00	$0.00
CB1	$14,012,936.00	6.3575215508%	6.3575215508%	$13,752,442.79	$72,859.54	$0.00	$0.00	$0.00	$72,859.54
CB2	$5,254,853.00	6.3575215508%	6.3575215508%	$5,157,168.02	$27,322.34	$0.00	$0.00	$0.00	$27,322.34
CB3	$3,503,233.00	6.3575215508%	6.3575215508%	$3,438,109.72	$18,214.88	$0.00	$0.00	$0.00	$18,214.88
CB4	$1,751,618.00	6.3575215508%	6.3575215508%	$1,719,056.34	$9,107.45	$0.00	$0.00	$0.00	$9,107.45
CB5	$1,751,617.00	6.3575215508%	6.3575215508%	$1,719,055.35	$9,107.44	$0.00	$0.00	$0.00	$9,107.44
CB6	$1,751,618.00	6.3575215508%	6.3575215508%	$1,719,057.13	$9,107.45	$0.00	$0.00	$0.00	$9,107.45
R	$50.00	0.0000000000%	0.0000000000%	$0.00	$0.01	$0.00	$0.00	$0.00	$0.01
R_SYN	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
Total	$875,808,599.00			$178,467,194.36	$940,796.71	$0.00	$0.00	$0.00	$940,796.71

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003
PER $1000 DENOMINATION
Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IA1	$35,000,000.00	6.5000000000%	6.5000000000%	0.00000143	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA2	$29,706,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA3	$3,000,000.00	6.7500000000%	6.7500000000%	286.70108000	1.61269333	0.00000000	0.00000000	0.00000000	1.61269333
IA4	$33,693,117.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41666656	0.00000000	0.00000000	0.00000000	5.41666656
IA5	$2,000,000.00	6.7500000000%	6.7500000000%	1,000.00000000	5.62500000	0.00000000	0.00000000	0.00000000	5.62500000
IA6	$2,475,000.00	6.7500000000%	6.7500000000%	1,000.00000000	5.62500202	0.00000000	0.00000000	0.00000000	5.62500202
IA7	$2,525,000.00	6.7500000000%	6.7500000000%	1,000.00000000	5.62500198	0.00000000	0.00000000	0.00000000	5.62500198
IA8	$3,000,000.00	6.7500000000%	6.7500000000%	1,000.00000000	5.62500000	0.00000000	0.00000000	0.00000000	5.62500000
IA9	$607,693.00	0.0000000000%	0.0000000000%	864.56348847	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA10	$2,800,000.00	6.7500000000%	6.7500000000%	1,000.00000000	5.62500000	0.00000000	0.00000000	0.00000000	5.62500000
IA11	$100,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA12	$11,142,877.00	6.5000000000%	6.5000000000%	429.71262628	2.32760983	0.00000000	0.00000000	0.00000000	2.32760983
IA13	$25,000,000.00	6.5000000000%	6.5000000000%	170.11301600	0.92144560	0.00000000	0.00000000	0.00000000	0.92144560
IA14	$89,762,051.00	6.2500000000%	6.2500000000%	0.00000145	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA15	$11,220,256.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA16	$11,220,256.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA17	$2,400,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA18	$2,500,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA19	$2,400,000.00	6.5000000000%	6.5000000000%	427.84953750	2.31751667	0.00000000	0.00000000	0.00000000	2.31751667
IA20	$2,000,000.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41666500	0.00000000	0.00000000	0.00000000	5.41666500
IA21	$1,700,000.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41666471	0.00000000	0.00000000	0.00000000	5.41666471
IA22	$112,000.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41669643	0.00000000	0.00000000	0.00000000	5.41669643
IIA1	$100,500,000.00	6.2500000000%	6.2500000000%	184.75836547	0.96228318	0.00000000	0.00000000	0.00000000	0.96228318
IIA2	$41,400,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA3	$5,200,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA4	$18,858,451.00	6.2500000000%	6.2500000000%	1,000.00000000	5.20833339	0.00000000	0.00000000	0.00000000	5.20833339
IIA5	$41,400,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA6	$50,733,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA7	$5,754,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA8	$10,240,000.00	6.2500000000%	6.2500000000%	914.05000586	4.76067676	0.00000000	0.00000000	0.00000000	4.76067676
IIA9	$15,000,000.00	6.2500000000%	6.2500000000%	441.62838800	2.30014800	0.00000000	0.00000000	0.00000000	2.30014800

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003
PER $1000 DENOMINATION
Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IIIA1	$87,377,000.00	5.5000000000%	5.5000000000%	118.26336072	0.54204035	0.00000000	0.00000000	0.00000000	0.54204035
IIIA2	$10,485,240.00	6.2500000000%	6.2500000000%	118.26336069	0.61595538	0.00000000	0.00000000	0.00000000	0.61595538
IIIA3	$4,610,000.00	6.2500000000%	6.2500000000%	1,000.00000000	5.20833406	0.00000000	0.00000000	0.00000000	5.20833406
IIIA4	$18,686,107.00	6.2500000000%	6.2500000000%	1,000.00000000	5.20833312	0.00000000	0.00000000	0.00000000	5.20833312
IIIA5	$2,969,080.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIIA6	$2,995,920.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIIA7	$34,468,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIIA8	$13,647,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIIA9	$21,761,187.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIIA10	$5,021,813.00	23.0750000000%	0.0000000000%	0.00000199	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIIA11	$520,000.00	6.2500000000%	6.2500000000%	1,000.00000000	5.20832692	0.00000000	0.00000000	0.00000000	5.20832692
CX	$6,399,262.00	6.2500000000%	6.2499999764%	135.24687691	0.70441091	0.00000000	0.00000000	0.00000000	0.70441091
CP	$3,597,122.00	0.0000000000%	0.0000000000%	456.81711379	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
CB1	$14,012,936.00	6.3575215508%	6.3575215508%	981.41051882	5.19944857	0.00000000	0.00000000	0.00000000	5.19944857
CB2	$5,254,853.00	6.3575215508%	6.3575215508%	981.41052090	5.19944897	0.00000000	0.00000000	0.00000000	5.19944897
CB3	$3,503,233.00	6.3575215508%	6.3575215508%	981.41051994	5.19944862	0.00000000	0.00000000	0.00000000	5.19944862
CB4	$1,751,618.00	6.3575215508%	6.3575215508%	981.41052444	5.19944988	0.00000000	0.00000000	0.00000000	5.19944988
CB5	$1,751,617.00	6.3575215508%	6.3575215508%	981.41051954	5.19944714	0.00000000	0.00000000	0.00000000	5.19944714
CB6	$1,751,618.00	6.3575215508%	6.3575215508%	981.41097545	5.19944988	0.00000000	0.00000000	0.00000000	5.19944988
R	$50.00	0.0000000000%	0.0000000000%	0.00000000	0.20000000	0.00000000	0.00000000	0.00000000	0.20000000
R_SYN	$0.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
SERIES: WAMMS 02MS1
WEIGHTED AVERAGE PC RATE: 6.46577%
WEIGHTED AVERAGE MATURITY: 331.36146
WEIGHTED AVERAGE LOAN AGE: 22.68544
POOL NUMBER: 1818
ISSUE DATE: 01/31/2002
CERTIFICATE BALANCE AT ISSUE: $376,531,676.04
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	190		$74,073,523.32
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$74,437.84
Unscheduled Principal Collection/Reversals		$22,946.53
Liquidations-in-full	19	$7,095,670.82
Subsequent Recoveries		$0.00
Net principal Distributed		$7,193,055.19	-$7,193,055.19

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	171		$66,880,468.13

SCHEDULED INTEREST AT MORTGAGE RATE:		$428,022.33

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Recoveries Carried Forward		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$28,903.97

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$7,592,173.55

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
SERIES: WAMMS 02MS1
WEIGHTED AVERAGE PC RATE: 6.20678%
WEIGHTED AVERAGE MATURITY: 330.97783
WEIGHTED AVERAGE LOAN AGE: 22.77268
POOL NUMBER: 1819
ISSUE DATE: 01/31/2002
CERTIFICATE BALANCE AT ISSUE: $300,006,640.45
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	150		$63,614,524.71
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$68,515.87
Unscheduled Principal Collection/Reversals		$48,446.25
Liquidations-in-full	8	$3,980,968.33
Subsequent Recoveries		$0.00
Net principal Distributed		$4,097,930.45	-$4,097,930.45

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	142		$59,516,594.26

SCHEDULED INTEREST AT MORTGAGE RATE:		$356,344.91

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Recoveries Carried Forward		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$27,310.23

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$4,426,965.13

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
SERIES: WAMMS 02MS1
WEIGHTED AVERAGE PC RATE: 6.25742%
WEIGHTED AVERAGE MATURITY: 333.09528
WEIGHTED AVERAGE LOAN AGE: 22.37843
POOL NUMBER: 1820
ISSUE DATE: 01/31/2002
CERTIFICATE BALANCE AT ISSUE: $199,270,283.49
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	94		$40,779,146.46
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$42,030.13
Unscheduled Principal Collection/Reversals		$5,501.74
Liquidations-in-full	13	$6,126,166.57
Subsequent Recoveries		$0.00
Net principal Distributed		$6,173,698.44	-$6,173,698.44

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	81		$34,605,448.02

SCHEDULED INTEREST AT MORTGAGE RATE:		$229,015.10

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Recoveries Carried Forward		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$16,371.43

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$6,386,342.11

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
SERIES: WAMMS 02MS1
WEIGHTED AVERAGE PC RATE: 6.32585%
WEIGHTED AVERAGE MATURITY: 331.59231
WEIGHTED AVERAGE LOAN AGE: 22.65170
POOL NUMBER: ALL
ISSUE DATE: 01/31/2002
CERTIFICATE BALANCE AT ISSUE: $875,808,599.98
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	434		$178,467,194.49
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$184,983.84
Unscheduled Principal Collection/Reversals		$76,894.52
Liquidations-in-full	40	$17,202,805.72
Subsequent Recoveries		$0.00
Net principal Distributed		$17,464,684.08	-$17,464,684.08

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	394		$161,002,510.41

SCHEDULED INTEREST AT MORTGAGE RATE:		$1,013,382.34

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Recoveries Carried Forward		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
10/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$72,585.63

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$18,405,480.79

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

Distribution by Group
Pool ID		Principal		Interest		Total
Pool - 1818		$7,193,055.19		$399,118.36		$7,592,173.55
Pool - 1819		$4,097,930.45		$329,034.68		$4,426,965.13
Pool - 1820		$6,173,698.44		$212,643.67		$6,386,342.11
Aggregate		$17,464,684.08		$940,796.71		$18,405,480.79

Number of Loans and Aggregate Principal Balance By Group
Pool ID	Beg Bal	Beg Count	Paid Off / Liq Count	Rem Count	Sched Prin End Bal	Sched Prin	Prin PrePay / Liq	Unsched Prin / Rev	Total Prin
Pool - 1818	$74,073,523.32	190	19	171	$66,880,468.13	$74,437.84	$7,095,670.82	$22,946.53	$7,193,055.19
Pool - 1819	$63,614,524.71	150	8	142	$59,516,594.26	$68,515.87	$3,980,968.33	$48,446.25	$4,097,930.45
Pool - 1820	$40,779,146.46	94	13	81	$34,605,448.02	$42,030.13	$6,126,166.57	$5,501.74	$6,173,698.44
Aggregate	$178,467,194.49	434	40	394	$161,002,510.41	$184,983.84	$17,202,805.72	$76,894.52	$17,464,684.08

Delinquency Information by Group
Pool ID	1 Month Count	Sched End Balance	2 Months Count	Sched End Balance	3 Months Count	Sched End Balance	4 Months Count	Sched End Balance
Pool - 1818	2	$710,363.95	0	$0.00	0	$0.00	1	$344,910.30
Pool - 1819	1	$341,980.27	0	$0.00	0	$0.00	0	$0.00
Pool - 1820	0	$0.00	0	$0.00	0	$0.00	1	$274,637.10
Aggregate	3	$1,052,344.22	0	$0.00	0	$0.00	2	$619,547.40

Foreclosure and REO Information by Group
Pool ID		Foreclosure Count		Sched End Balance		REO Count		Sched End Balance
Pool - 1818		3		$970,940.57		0		$0.00
Pool - 1819		0		$0.00		0		$0.00
Pool - 1820		1		$373,988.66		0		$0.00
Aggregate		4		$1,344,929.23		0		$0.00

Aggregate Loss Amounts by Group
Pool ID			Count			Loss Amount
Group 1(1818)			0			$0.00
Group 2(1819)			0			$0.00
Group 3(1820)			0			$0.00
Aggregate			0			$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

INSURANCE RESERVES - Group 1(1818)
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$8,758,086.00	$0.00	$0.00	$0.00	$8,758,086.00
Bankruptcy Bond
Single-Units	$212,147.00	$0.00	$0.00	$0.00	$212,147.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$8,758,086.00	$0.00	$0.00	$0.00	$8,758,086.00

INSURANCE RESERVES - Group 2(1819)
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$8,758,086.00	$0.00	$0.00	$0.00	$8,758,086.00
Bankruptcy Bond
Single-Units	$212,147.00	$0.00	$0.00	$0.00	$212,147.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$8,758,086.00	$0.00	$0.00	$0.00	$8,758,086.00

INSURANCE RESERVES - Group 3(1820)
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$8,758,086.00	$0.00	$0.00	$0.00	$8,758,086.00
Bankruptcy Bond
Single-Units	$212,147.00	$0.00	$0.00	$0.00	$212,147.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$8,758,086.00	$0.00	$0.00	$0.00	$8,758,086.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

INSURANCE RESERVES - Aggregate
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$26,274,258.00	$0.00	$0.00	$0.00	$26,274,258.00
Bankruptcy Bond
Single-Units	$636,441.00	$0.00	$0.00	$0.00	$636,441.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$26,274,258.00	$0.00	$0.00	$0.00	$26,274,258.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.02MS1
Distribution Date: 10/27/2003

The Class Principal Balances of each Class of the Class CB1,CB2,CB3,CB4,CB5,CB6 Certificatesimmediately after the principal and interest distribution on 200310 are as follows:

Class			Class Principal Balance
CB1			$13,738,215.56
CB2			$5,151,832.81
CB3			$3,434,552.91
CB4			$1,717,277.94
CB5			$1,717,276.95
CB6			$1,717,278.73
Total			$27,476,434.90
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.

The Class Principal Balances of each Class of the Class CB1,CB2,CB3,CB4,CB5,CB6 Certificatesimmediately after the principal and interest distribution on 200310 are as follows:

Class			Class Principal Balance
CB1			$13,738,215.56
CB2			$5,151,832.81
CB3			$3,434,552.91
CB4			$1,717,277.94
CB5			$1,717,276.95
CB6			$1,717,278.73
Total			$27,476,434.90
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.

The Class Principal Balances of each Class of the Class CB1,CB2,CB3,CB4,CB5,CB6 Certificatesimmediately after the principal and interest distribution on 200310 are as follows:

Class			Class Principal Balance
CB1			$13,738,215.56
CB2			$5,151,832.81
CB3			$3,434,552.91
CB4			$1,717,277.94
CB5			$1,717,276.95
CB6			$1,717,278.73
Total			$27,476,434.90
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.

WASHINGTON MUTUAL MSC MORT PASS THROUGH CERT SER 2002-MS1 8-K