Is ICD-10-CM code W51 billable?

No, W51 (Accidental striking against or bumped into by another person) 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 W51 belong to?

W51 belongs to Chapter 20 of the ICD-10-CM tabular list: V00–Y99 (External Causes of Morbidity).

W51Not billable, use a more specific code below

Accidental striking against or bumped into by another person

In Exposure to animate mechanical forces (W50-W64), chapter 20: External Causes of Morbidity

3 billable codes under W51: none are a CC or MCC; none map to an HCC.

Instructional notes

Excludes1: not coded here, use a different code

assault by striking against or bumping into by another person (Y04.2)
fall due to collision with another person (W03)

Also applies, from Exposure to animate mechanical forces (W50-W64)

These notes sit on W50-W64 and apply to every code under it, including W51.

Excludes1: not coded here, use a different code

Toxic effect of contact with venomous animals and plants (T63.-)

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 W51

W51 can't be used on a claim. Pick a billable code below; grey headings group them.

W51 MS-DRGs

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

Other codes that refer to W51

Notes on these codes point to W51.

V00 Excludes1: collision with another person without fall (W51)
V00-V09 Excludes1: struck or bumped by another person (W51)
W03 Excludes1: collision with another person without fall (W51)
W18.4 Excludes1: collision with another person without fall (W51)

Code history

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