Is ICD-10-CM code W40 billable?

No, W40 (Explosion of other materials) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code W40 belong to?

W40 belongs to Chapter 20 of the ICD-10-CM tabular list: V00–Y99 (External Causes of Morbidity).

W40Not billable, use a more specific code below

Explosion of other materials

In Exposure to inanimate mechanical forces (W20-W49), chapter 20: External Causes of Morbidity

12 billable codes under W40: none are a CC or MCC; none map to an HCC.

Instructional notes

Excludes1: not coded here, use a different code

assault by explosive material (X96)
explosion involving legal intervention (Y35.1-)
explosion involving military or war operations (Y36.0-, Y36.2-)
intentional self-harm by explosive material (X75)

Also applies, from Exposure to inanimate mechanical forces (W20-W49)

These notes sit on W20-W49 and apply to every code under it, including W40.

Excludes1: not coded here, use a different code

assault (X92-Y09)
contact or collision with animals or persons (W50-W64)
exposure to inanimate mechanical forces involving military or war operations (Y36.-, Y37.-)
intentional self-harm (X71-X83)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers how to report external cause codes (V00-Y99) describing cause, intent, place, activity, and status. They are never principal or first-listed, and reporting is voluntary unless required.

General External Cause Coding Guidelines (page 88)
Place of Occurrence Guideline (page 89)
Activity Code (page 89)
Place of Occurrence, Activity, and Status Codes Used with other External Cause Code (page 89)
If the Reporting Format Limits the Number of External Cause Codes (page 90)
Multiple External Cause Coding Guidelines (page 90)
Child and Adult Abuse Guideline (page 90)
Unknown or Undetermined Intent Guideline (page 91)

Read Section I.C.20 (page 87), 3 more topics

All codes under W40

W40 can't be used on a claim. Pick a billable code below; grey headings group them.

W40 MS-DRGs

This code does not group to an MS-DRG as a principal diagnosis.

Other codes that refer to W40

Notes on these codes point to W40.

W20 Excludes1: object set in motion by explosion (W35-W40)
W25 Code First: injury due to flying glass from explosion or firearm discharge (W32-W40)
X00-X08 Excludes2: explosions (W35-W40)

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.