MCMedicalCodingSoftware
W33.10

W33.10: Accidental malfunction of unspecified larger firearm

Non-billable headerICD-10-CM

W33.10 is a non-billable header ICD-10-CM code for accidental malfunction of unspecified larger firearm. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

The appropriate 7th character is to be added to each code from category W33

A
initial encounter
D
subsequent encounter
S
sequela

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Malfunction of unspecified larger firearm NOS

Excludes1 inherited from the categories above W33.10

A category’s note binds every code beneath it.

Written on W33: Accidental rifle, shotgun and larger firearm discharge and malfunction

  • accidental airgun discharge and malfunction (W34.010, W34.110)
  • accidental BB gun discharge and malfunction (W34.010, W34.110)
  • accidental handgun discharge and malfunction (W32.-)
  • accidental pellet gun discharge and malfunction (W34.010, W34.110)
  • assault by rifle, shotgun and larger firearm discharge (X94)
  • firearm discharge involving legal intervention (Y35.0-)
  • firearm discharge involving military or war operations (Y36.4-)
  • intentional self-harm by rifle, shotgun and larger firearm discharge (X73)

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Alphabetic index entries that lead here

  • Powder burn›larger firearm
  • Recoil›larger firearm
  • Explosion›firearm NEC›larger firearm
  • Malfunction›firearm›larger firearm

Code history

Unchanged in every release from FY2024 to FY2027.

Code to one of these instead W33.10

3 child codes. Green means billable.

Other codes under W33.1

ICD-10-CMFY2027· effective October 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release: see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.