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Compare/W33 vs Y36.4

W33 vs Y36.4

W33 (Accidental rifle, shotgun and larger firearm discharge and malfunction) compared with Y36.4 (War operations involving firearm discharge and other forms of conventional warfare), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. W33 carries an Excludes1 note covering Y36.4: “firearm discharge involving military or war operations (Y36.4-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. W33 carries an Excludes1 note covering Y36.4: “exposure to inanimate mechanical forces involving military or war operations (Y36.-, Y37.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

W33Accidental rifle, shotgun and larger firearm discharge and malfunctionY36.4War operations involving firearm discharge and other forms of conventional warfare
Billing statusNon-billable header

Report instead: W33.00XA, W33.00XD, W33.00XS, W33.01XA, W33.01XD

Non-billable header

Report instead: Y36.410A, Y36.410D, Y36.410S, Y36.411A, Y36.411D

ClassificationV00-Y99 — External Causes of Morbidity (V00-Y99)V00-Y99 — External Causes of Morbidity (V00-Y99)
DefinitionAccidental rifle, shotgun and larger firearm discharge and malfunction is a non-billable ICD-10-CM category code (W33).War operations involving firearm discharge and other forms of conventional warfare is a non-billable ICD-10-CM category code (Y36.4).
7th characterThe appropriate 7th character is to be added to each code from category W33The appropriate 7th character is to be added to each code from category Y36
Includes
rifle, shotgun and larger firearm discharge and malfunction NOS
injuries to military personnel and civilians caused by war, civil insurrection, and peacekeeping missions

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources