WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003

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
A1	939336TF0	$50,000,000.00	$23,309,051.74	5.0000000000%	5.0000000000%	$97,121.05	$907,358.10	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,004,479.15	$22,401,693.64
A2	939336TG8	$90,614,734.00	$42,242,870.45	4.7500000000%	4.7500000000%	$167,211.36	$1,644,400.26	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,811,611.62	$40,598,470.19
A3	939336TH6	$90,000,000.00	$41,956,293.12	5.7500000000%	5.7500000000%	$201,040.57	$1,633,244.58	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,834,285.15	$40,323,048.54
A4	939336TJ2	$50,000,000.00	$23,309,051.74	5.5000000000%	5.5000000000%	$106,833.15	$907,358.10	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,014,191.26	$22,401,693.64
A5	939336TK9	$51,496,266.00	$24,006,582.55	1.6750000000%	1.6750000000%	$33,509.19	$934,511.08	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$968,020.27	$23,072,071.47
A6	939336TL7	$51,496,266.00	$24,006,582.55	6.8250000000%	6.8250000000%	$136,537.44	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$136,537.44	$23,072,071.47
A7	939336TM5	$2,000,000.00	$932,362.08	5.2500000000%	5.2500000000%	$4,079.08	$36,294.32	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$40,373.41	$896,067.76
A8	939336TN3	$35,000,000.00	$35,000,000.00	5.7500000000%	5.7500000000%	$167,708.33	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$167,708.33	$35,000,000.00
A9	939336TP8	$963,000.00	$963,000.00	5.7500000000%	5.7500000000%	$4,614.38	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$4,614.38	$963,000.00
A10	939336TQ6	$27,000,000.00	$27,000,000.00	5.5000000000%	5.5000000000%	$123,750.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$123,750.00	$27,000,000.00
A11	939336TR4	$27,000,000.00	$27,000,000.00	0.2000000000%	0.2000000000%	$4,500.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$4,500.00	$27,000,000.00
A12	939336TS2	$32,130,000.00	$32,130,000.00	5.5000000000%	5.5000000000%	$147,262.50	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$147,262.50	$32,130,000.00
A13	939336TT0	$3,570,000.00	$3,570,000.00	5.5000000000%	5.5000000000%	$16,362.50	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$16,362.50	$3,570,000.00
A14	939336TU7	$35,700,000.00	$35,700,000.00	0.2500000000%	0.2500000000%	$7,437.50	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$7,437.50	$35,700,000.00
A15	939336TV5	$10,250,000.00	$10,250,000.00	5.7500000000%	5.7500000000%	$49,114.58	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$49,114.58	$10,250,000.00
X	939336TW3	$16,365,793.00	$8,413,337.94	5.7500000000%	5.7500000000%	$40,313.91	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$40,313.91	$8,186,558.93
P	939336TX1	$3,874,662.98	$3,192,087.04	0.0000000000%	0.0000000000%	$0.00	$11,403.55	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$11,403.55	$3,180,683.49
B1	939336TY9	$5,973,000.00	$5,911,969.92	5.7500000000%	5.7500000000%	$28,328.19	$7,119.37	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$35,447.56	$5,904,850.55
B2	939336TZ6	$2,298,000.00	$2,274,519.81	5.7500000000%	5.7500000000%	$10,898.74	$2,739.05	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$13,637.79	$2,271,780.76
B3	939336UA9	$1,839,000.00	$1,820,209.73	5.7500000000%	5.7500000000%	$8,721.84	$2,191.95	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$10,913.79	$1,818,017.78
B4	939336UX9	$919,000.00	$909,609.98	5.7500000000%	5.7500000000%	$4,358.55	$1,095.38	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$5,453.93	$908,514.60
B5	939336UY7	$689,000.00	$681,960.04	5.7500000000%	5.7500000000%	$3,267.73	$821.24	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$4,088.96	$681,138.80
B6	939336UZ4	$919,912.87	$910,513.48	5.7500000000%	5.7500000000%	$4,362.88	$1,096.47	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$5,459.35	$909,417.01
R	939336YV9	$100.00	$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
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
A10_ROUND	XXXXXXXXX	$27,000,000.00	$27,000,000.00	5.5000000000%	5.5000000000%	$123,750.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$123,750.00	$27,000,000.00
A10_PREMIUM	XXXXXXXXX	$0.00	$0.00	0.0000000000%	0.0000000000%	$1,125.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,125.00	$0.00
Total		$459,536,675.85	$280,370,081.68			$1,368,458.47	$6,089,633.46	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$7,458,091.93	$274,280,448.22

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003

Class	Orig Face	Beg Bal	Prin Loss	Prin Reimbursed	Subsequent Recoveries	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
A1	$50,000,000.00	$23,309,051.74	$0.00	$0.00	$0.00	$0.00	$907,358.10	0.4480338728	$22,401,693.64
A2	$90,614,734.00	$42,242,870.45	$0.00	$0.00	$0.00	$0.00	$1,644,400.26	0.4480338726	$40,598,470.19
A3	$90,000,000.00	$41,956,293.12	$0.00	$0.00	$0.00	$0.00	$1,633,244.58	0.4480338727	$40,323,048.54
A4	$50,000,000.00	$23,309,051.74	$0.00	$0.00	$0.00	$0.00	$907,358.10	0.4480338728	$22,401,693.64
A5	$51,496,266.00	$24,006,582.55	$0.00	$0.00	$0.00	$0.00	$934,511.08	0.4480338724	$23,072,071.47
A6	$51,496,266.00	$24,006,582.55	$0.00	$0.00	$0.00	$0.00	$0.00	0.4480338724	$23,072,071.47
A7	$2,000,000.00	$932,362.08	$0.00	$0.00	$0.00	$0.00	$36,294.32	0.4480338800	$896,067.76
A8	$35,000,000.00	$35,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$35,000,000.00
A9	$963,000.00	$963,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$963,000.00
A10	$27,000,000.00	$27,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$27,000,000.00
A11	$27,000,000.00	$27,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$27,000,000.00
A12	$32,130,000.00	$32,130,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$32,130,000.00
A13	$3,570,000.00	$3,570,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$3,570,000.00
A14	$35,700,000.00	$35,700,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$35,700,000.00
A15	$10,250,000.00	$10,250,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$10,250,000.00
X	$16,365,793.00	$8,413,337.94	$0.00	$0.00	$0.00	$0.00	$0.00	0.5002237857	$8,186,558.93
P	$3,874,662.98	$3,192,087.04	$0.00	$0.00	$0.00	$0.00	$11,403.55	0.8208929412	$3,180,683.49
B1	$5,973,000.00	$5,911,969.92	$0.00	$0.00	$0.00	$0.00	$7,119.37	0.9885904152	$5,904,850.55
B2	$2,298,000.00	$2,274,519.81	$0.00	$0.00	$0.00	$0.00	$2,739.05	0.9885904091	$2,271,780.76
B3	$1,839,000.00	$1,820,209.73	$0.00	$0.00	$0.00	$0.00	$2,191.95	0.9885904187	$1,818,017.78
B4	$919,000.00	$909,609.98	$0.00	$0.00	$0.00	$0.00	$1,095.38	0.9885904244	$908,514.60
B5	$689,000.00	$681,960.04	$0.00	$0.00	$0.00	$0.00	$821.24	0.9885904209	$681,138.80
B6	$919,912.87	$910,513.48	$0.00	$0.00	$0.00	$0.00	$1,096.47	0.9885903760	$909,417.01
R	$100.00	$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
A10_ROUND	$27,000,000.00	$27,000,000.00	$0.00	$0.00	$0.00	$0.00	$0.00	1.0000000000	$27,000,000.00
A10_PREMIUM	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
Total	$459,536,675.85	$280,370,081.68	$0.00	$0.00	$0.00	$0.00	$6,089,633.46	0.5968630202	$274,280,448.22

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003
PER $1000 DENOMINATION
Class	Orig Face	Beg Bal	Prin Loss	Prin Reimbursed	Subsequent Recoveries	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
A1	$50,000,000.00	466.18103480	0.00000000	0.00000000	0.00000000	0.00000000	18.14716200	0.4480338728	448.03387280
A2	$90,614,734.00	466.18103464	0.00000000	0.00000000	0.00000000	0.00000000	18.14716203	0.4480338726	448.03387262
A3	$90,000,000.00	466.18103467	0.00000000	0.00000000	0.00000000	0.00000000	18.14716200	0.4480338727	448.03387267
A4	$50,000,000.00	466.18103480	0.00000000	0.00000000	0.00000000	0.00000000	18.14716200	0.4480338728	448.03387280
A5	$51,496,266.00	466.18103437	0.00000000	0.00000000	0.00000000	0.00000000	18.14716197	0.4480338724	448.03387240
A6	$51,496,266.00	466.18103437	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.4480338724	448.03387240
A7	$2,000,000.00	466.18104000	0.00000000	0.00000000	0.00000000	0.00000000	18.14716000	0.4480338800	448.03388000
A8	$35,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A9	$963,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A10	$27,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A11	$27,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A12	$32,130,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A13	$3,570,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A14	$35,700,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A15	$10,250,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
X	$16,365,793.00	514.08067669	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.5002237857	500.22378567
P	$3,874,662.98	823.83604883	0.00000000	0.00000000	0.00000000	0.00000000	2.94310758	0.8208929412	820.89294125
B1	$5,973,000.00	989.78234053	0.00000000	0.00000000	0.00000000	0.00000000	1.19192533	0.9885904152	988.59041520
B2	$2,298,000.00	989.78233681	0.00000000	0.00000000	0.00000000	0.00000000	1.19192776	0.9885904091	988.59040905
B3	$1,839,000.00	989.78234367	0.00000000	0.00000000	0.00000000	0.00000000	1.19192496	0.9885904187	988.59041871
B4	$919,000.00	989.78235038	0.00000000	0.00000000	0.00000000	0.00000000	1.19192601	0.9885904244	988.59042437
B5	$689,000.00	989.78235123	0.00000000	0.00000000	0.00000000	0.00000000	1.19193033	0.9885904209	988.59042090
B6	$919,912.87	989.78230406	0.00000000	0.00000000	0.00000000	0.00000000	1.19192810	0.9885903760	988.59037596
R	$100.00	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
A10_ROUND	$27,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
A10_PREMIUM	$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.03MS7
Distribution Date: 12/26/2003

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
A1	$50,000,000.00	5.0000000000%	5.0000000000%	$23,309,051.74	$97,121.05	$0.00	$0.00	$0.00	$97,121.05
A2	$90,614,734.00	4.7500000000%	4.7500000000%	$42,242,870.45	$167,211.36	$0.00	$0.00	$0.00	$167,211.36
A3	$90,000,000.00	5.7500000000%	5.7500000000%	$41,956,293.12	$201,040.57	$0.00	$0.00	$0.00	$201,040.57
A4	$50,000,000.00	5.5000000000%	5.5000000000%	$23,309,051.74	$106,833.15	$0.00	$0.00	$0.00	$106,833.15
A5	$51,496,266.00	1.6750000000%	1.6750000000%	$24,006,582.55	$33,509.19	$0.00	$0.00	$0.00	$33,509.19
A6	$51,496,266.00	6.8250000000%	6.8250000000%	$24,006,582.55	$136,537.44	$0.00	$0.00	$0.00	$136,537.44
A7	$2,000,000.00	5.2500000000%	5.2500000000%	$932,362.08	$4,079.08	$0.00	$0.00	$0.00	$4,079.08
A8	$35,000,000.00	5.7500000000%	5.7500000000%	$35,000,000.00	$167,708.33	$0.00	$0.00	$0.00	$167,708.33
A9	$963,000.00	5.7500000000%	5.7500000000%	$963,000.00	$4,614.38	$0.00	$0.00	$0.00	$4,614.38
A10	$27,000,000.00	5.5000000000%	5.5000000000%	$27,000,000.00	$123,750.00	$0.00	$0.00	$0.00	$123,750.00
A11	$27,000,000.00	0.2000000000%	0.2000000000%	$27,000,000.00	$4,500.00	$0.00	$0.00	$0.00	$4,500.00
A12	$32,130,000.00	5.5000000000%	5.5000000000%	$32,130,000.00	$147,262.50	$0.00	$0.00	$0.00	$147,262.50
A13	$3,570,000.00	5.5000000000%	5.5000000000%	$3,570,000.00	$16,362.50	$0.00	$0.00	$0.00	$16,362.50
A14	$35,700,000.00	0.2500000000%	0.2500000000%	$35,700,000.00	$7,437.50	$0.00	$0.00	$0.00	$7,437.50
A15	$10,250,000.00	5.7500000000%	5.7500000000%	$10,250,000.00	$49,114.58	$0.00	$0.00	$0.00	$49,114.58
X	$16,365,793.00	5.7500000000%	5.7500000000%	$8,413,337.94	$40,313.91	$0.00	$0.00	$0.00	$40,313.91
P	$3,874,662.98	0.0000000000%	0.0000000000%	$3,192,087.04	$0.00	$0.00	$0.00	$0.00	$0.00
B1	$5,973,000.00	5.7500000000%	5.7500000000%	$5,911,969.92	$28,328.19	$0.00	$0.00	$0.00	$28,328.19
B2	$2,298,000.00	5.7500000000%	5.7500000000%	$2,274,519.81	$10,898.74	$0.00	$0.00	$0.00	$10,898.74
B3	$1,839,000.00	5.7500000000%	5.7500000000%	$1,820,209.73	$8,721.84	$0.00	$0.00	$0.00	$8,721.84
B4	$919,000.00	5.7500000000%	5.7500000000%	$909,609.98	$4,358.55	$0.00	$0.00	$0.00	$4,358.55
B5	$689,000.00	5.7500000000%	5.7500000000%	$681,960.04	$3,267.73	$0.00	$0.00	$0.00	$3,267.73
B6	$919,912.87	5.7500000000%	5.7500000000%	$910,513.48	$4,362.88	$0.00	$0.00	$0.00	$4,362.88
R	$100.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
R_SYN	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
A10_ROUND	$27,000,000.00	5.5000000000%	5.5000000000%	$27,000,000.00	$123,750.00	$0.00	$0.00	$0.00	$123,750.00
A10_PREMIUM	$0.00	0.0000000000%	0.0000000000%	$0.00	$1,125.00	$0.00	$0.00	$0.00	$1,125.00
Total	$459,536,675.85			$280,370,081.68	$1,368,458.47	$0.00	$0.00	$0.00	$1,368,458.47

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003
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
A1	$50,000,000.00	5.0000000000%	5.0000000000%	466.18103480	1.94242100	0.00000000	0.00000000	0.00000000	1.94242100
A2	$90,614,734.00	4.7500000000%	4.7500000000%	466.18103464	1.84529990	0.00000000	0.00000000	0.00000000	1.84529990
A3	$90,000,000.00	5.7500000000%	5.7500000000%	466.18103467	2.23378411	0.00000000	0.00000000	0.00000000	2.23378411
A4	$50,000,000.00	5.5000000000%	5.5000000000%	466.18103480	2.13666300	0.00000000	0.00000000	0.00000000	2.13666300
A5	$51,496,266.00	1.6750000000%	1.6750000000%	466.18103437	0.65071106	0.00000000	0.00000000	0.00000000	0.65071106
A6	$51,496,266.00	6.8250000000%	6.8250000000%	466.18103437	2.65140467	0.00000000	0.00000000	0.00000000	2.65140467
A7	$2,000,000.00	5.2500000000%	5.2500000000%	466.18104000	2.03954000	0.00000000	0.00000000	0.00000000	2.03954000
A8	$35,000,000.00	5.7500000000%	5.7500000000%	1,000.00000000	4.79166657	0.00000000	0.00000000	0.00000000	4.79166657
A9	$963,000.00	5.7500000000%	5.7500000000%	1,000.00000000	4.79167186	0.00000000	0.00000000	0.00000000	4.79167186
A10	$27,000,000.00	5.5000000000%	5.5000000000%	1,000.00000000	4.58333333	0.00000000	0.00000000	0.00000000	4.58333333
A11	$27,000,000.00	0.2000000000%	0.2000000000%	1,000.00000000	0.16666667	0.00000000	0.00000000	0.00000000	0.16666667
A12	$32,130,000.00	5.5000000000%	5.5000000000%	1,000.00000000	4.58333333	0.00000000	0.00000000	0.00000000	4.58333333
A13	$3,570,000.00	5.5000000000%	5.5000000000%	1,000.00000000	4.58333333	0.00000000	0.00000000	0.00000000	4.58333333
A14	$35,700,000.00	0.2500000000%	0.2500000000%	1,000.00000000	0.20833333	0.00000000	0.00000000	0.00000000	0.20833333
A15	$10,250,000.00	5.7500000000%	5.7500000000%	1,000.00000000	4.79166634	0.00000000	0.00000000	0.00000000	4.79166634
X	$16,365,793.00	5.7500000000%	5.7500000000%	514.08067669	2.46330318	0.00000000	0.00000000	0.00000000	2.46330318
P	$3,874,662.98	0.0000000000%	0.0000000000%	823.83604883	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
B1	$5,973,000.00	5.7500000000%	5.7500000000%	989.78234053	4.74270718	0.00000000	0.00000000	0.00000000	4.74270718
B2	$2,298,000.00	5.7500000000%	5.7500000000%	989.78233681	4.74270670	0.00000000	0.00000000	0.00000000	4.74270670
B3	$1,839,000.00	5.7500000000%	5.7500000000%	989.78234367	4.74270799	0.00000000	0.00000000	0.00000000	4.74270799
B4	$919,000.00	5.7500000000%	5.7500000000%	989.78235038	4.74270947	0.00000000	0.00000000	0.00000000	4.74270947
B5	$689,000.00	5.7500000000%	5.7500000000%	989.78235123	4.74271408	0.00000000	0.00000000	0.00000000	4.74271408
B6	$919,912.87	5.7500000000%	5.7500000000%	989.78230406	4.74271004	0.00000000	0.00000000	0.00000000	4.74271004
R	$100.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
R_SYN	$0.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
A10_ROUND	$27,000,000.00	5.5000000000%	5.5000000000%	1,000.00000000	4.58333333	0.00000000	0.00000000	0.00000000	4.58333333
A10_PREMIUM	$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
12/2003 DISTRIBUTION REPORT
SERIES: WAMMS 03MS7
WEIGHTED AVERAGE PC RATE: 5.85708%
WEIGHTED AVERAGE MATURITY: 335.49121
WEIGHTED AVERAGE LOAN AGE: 11.01145
POOL NUMBER: 2047
ISSUE DATE: 02/27/2003
CERTIFICATE BALANCE AT ISSUE: $459,536,675.85
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	635		$280,370,081.69
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$341,601.37
Unscheduled Principal Collection/Reversals		$74,559.19
Liquidations-in-full	13	$5,673,472.90
Subsequent Recoveries		$0.00
Net principal Distributed		$6,089,633.46	-$6,089,633.46

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	622		$274,280,448.23

SCHEDULED INTEREST AT MORTGAGE RATE:		$1,434,048.21

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
12/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$65,589.74

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:		$7,458,091.93

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
12/2003 DISTRIBUTION REPORT
SERIES: WAMMS 03MS7
WEIGHTED AVERAGE PC RATE: 5.85708%
WEIGHTED AVERAGE MATURITY: 335.49121
WEIGHTED AVERAGE LOAN AGE: 11.01145
POOL NUMBER: ALL
ISSUE DATE: 02/27/2003
CERTIFICATE BALANCE AT ISSUE: $459,536,675.85
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	635		$280,370,081.69
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$341,601.37
Unscheduled Principal Collection/Reversals		$74,559.19
Liquidations-in-full	13	$5,673,472.90
Subsequent Recoveries		$0.00
Net principal Distributed		$6,089,633.46	-$6,089,633.46

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	622		$274,280,448.23

SCHEDULED INTEREST AT MORTGAGE RATE:		$1,434,048.21

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
12/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$65,589.74

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:		$7,458,091.93

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003

Distribution by Group
Pool ID		Principal		Interest		Total
Pool - 2047		$6,089,633.46		$1,368,458.47		$7,458,091.93
Aggregate		$6,089,633.46		$1,368,458.47		$7,458,091.93

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 - 2047	$280,370,081.69	635	13	622	$274,280,448.23	$341,601.37	$5,673,472.90	$74,559.19	$6,089,633.46
Aggregate	$280,370,081.69	635	13	622	$274,280,448.23	$341,601.37	$5,673,472.90	$74,559.19	$6,089,633.46

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 - 2047	2	$1,069,829.77	2	$798,129.55	0	$0.00	0	$0.00
Aggregate	2	$1,069,829.77	2	$798,129.55	0	$0.00	0	$0.00

Foreclosure and REO Information by Group
Pool ID		Foreclosure Count		Sched End Balance		REO Count		Sched End Balance
Pool - 2047		0		$0.00		0		$0.00
Aggregate		0		$0.00		0		$0.00

Aggregate Loss Amounts by Group
Pool ID			Count			Loss Amount
Group 1(2047)			0			$0.00
Aggregate			0			$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003

INSURANCE RESERVES - Group 1(2047)
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	$4,595,366.00	$0.00	$0.00	$0.00	$4,595,366.00
Bankruptcy Bond
Single-Units	$106,577.00	$0.00	$0.00	$0.00	$106,577.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$4,595,366.00	$0.00	$0.00	$0.00	$4,595,366.00

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	$4,595,366.00	$0.00	$0.00	$0.00	$4,595,366.00
Bankruptcy Bond
Single-Units	$106,577.00	$0.00	$0.00	$0.00	$106,577.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$4,595,366.00	$0.00	$0.00	$0.00	$4,595,366.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMMS.03MS7
Distribution Date: 12/26/2003

The Group B Certificates provide, to the limited extent described in the Prospectus Supplement, credit support, as well as special hazard, bankruptcy, and fraud coverage to certain Certificates. The "Prospectus Supplement" is that certain Prospectus Supplement, dated February 25, 2003 to that certain Prospectus Supplement, dated November 21, 2002, to which certain certificates were offered. The special hazard, bankruptcy, and Fraud coverage (collectively, "Credit Enhancements") provided by the B certificates provide coverage to the Loans, subject to the conditions and limitations to payment specified thereunder.



The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200312 are as follows:

Class			Class Principal Balance
B1			$5,904,850.55
B2			$2,271,780.76
B3			$1,818,017.78
B4			$908,514.60
B5			$681,138.80
B6			$909,417.01
Total			$12,493,719.50
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.
The amount of the special hazard coverage, bankruptcy coverage, and fraud coverage, as of the above referenced distribution date, is $4,595,366.00, $106,577.00, $4,595,366.00 respectively, and such coverages are referred to in the table above under the column "Insurance Type" as "special hazard," "bankruptcy bond," and "mortgage repurchase," respectively. However, no policy of insurance exists for any such coverage, notwithstanding the reference to "insurance."

WASHINGTON MUTUAL MSC MORT PASS THRU CERT SERIES 2003-MS7 8-K