Table 1.

Firearm diagnosis codes from CDC’s external cause-of-injury matrices

Intent	ICD-9-CM (2000–2014)	ICD-10-CM (2016–2020)
Unintentional	E9220, E9221, E9222, E9223, E9228, E9229	W320XX, W321XX, W3300X, W3301X, W3302X, W3303X, W3309X, W3310X, W3311X, W3312X, W3313X, W3319X, W3400X, W3409X, W3410X, W3419X
Self-Harm	E9550, E9551, E9552, E9553, E9554	X72XXX, X730XX, X731XX, X732XX, X738XX, X739XX, X748XX, X749XX
Assault	E9650, E9651, E9652, E9653, E9654, E9794	Y384X1, Y384X2, Y384X3, X93XXX, X940XX, X941XX, X942XX, X948XX, X949XX, X958XX, X959XX
Undetermined	E9850, E9851, E9852, E9853, E9854	Y22XXX, Y230XX, Y231XX, Y232XX, Y233XX, Y238XX, Y239XX, Y248XX, Y249XX
Legal intervention or war	E970	Y35001, Y35002, Y35003, Y35009, Y35011, Y35012, Y35013, Y35019, Y35021, Y35022, Y35023, Y35029, Y35031, Y35032, Y35033, Y35039, Y35091, Y35092, Y35093, Y35099, Y36420, Y36421, Y36430, Y36431, Y3692X, Y37420, Y37421, Y37430, Y37431, Y3792X

Only initial encounters were considered for each diagnosis code under ICD-10-CM