Is W33.1 a billable ICD-10-CM code?

No. W33.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does W33.1 sit in the tabular list?

External causes of morbidity (V00-Y99), in the block Exposure to inanimate mechanical forces (W20-W49).

What cannot be coded together with W33.1?

W33.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above W33.1 (W33) and apply to it just the same.

W33.1

W33.1 — Accidental rifle, shotgun and larger firearm malfunction

Non-billable headerICD-10-CM

W33.1 is a non-billable header ICD-10-CM code for accidental rifle, shotgun and larger firearm malfunction. 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.

Injury due to explosion of rifle, shotgun and larger firearm (parts)
Injury due to malfunction of mechanism or component of rifle, shotgun and larger firearm
Injury due to piercing, cutting, crushing or pinching due to (by) slide trigger mechanism, scope or other gun part
Injury due to recoil of rifle, shotgun and larger firearm
Powder burn from rifle, shotgun and larger firearm

Excludes1 inherited from the categories above W33.1

These are not written on W33.1, but they bind it: a note on a category applies to every code beneath it. Billing W33.1 with anything listed here is a denial.

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)

Other codes that can never be billed with W33.1

These codes carry an Excludes1 note pointing at W33.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading W33.1 alone.

W23Caught, crushed, jammed or pinched in or between objects
W32Accidental handgun discharge and malfunction

Risk adjustment

W33.1 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code history

W33.1 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead W33.1

5 child codes. Green means billable.

Related codes at this level

Codes that share W33. If W33.1 is not quite right, the correct code is usually one of these.

W33.0Accidental rifle, shotgun and larger firearm discharge

Questions about W33.1

Is W33.1 a billable ICD-10-CM code?: No. W33.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does W33.1 sit in the tabular list?: External causes of morbidity (V00-Y99), in the block Exposure to inanimate mechanical forces (W20-W49).
What cannot be coded together with W33.1?: W33.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above W33.1 (W33) and apply to it just the same.