Is W51 a billable ICD-10-CM code?

No. W51 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does W51 sit in the tabular list?

External causes of morbidity (V00-Y99), in the block Exposure to animate mechanical forces (W50-W64).

What cannot be coded together with W51?

W51 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

W51

W51 — Accidental striking against or bumped into by another person

Non-billable headerICD-10-CM

W51 is a non-billable header ICD-10-CM code for accidental striking against or bumped into by another person. 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 code W51

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

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

Other codes that can never be billed with W51

These codes carry an Excludes1 note pointing at W51. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading W51 alone.

V00Pedestrian conveyance accident
W03Other fall on same level due to collision with another person
W03.XXXAOther fall on same level due to collision with another person, initial encounter
W03.XXXDOther fall on same level due to collision with another person, subsequent encounter
W03.XXXSOther fall on same level due to collision with another person, sequela
W18.4Slipping, tripping and stumbling without falling

Risk adjustment

W51 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.

How W51 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to W51.

Bumping against, into›person(s)
Collision NEC›pedestrian
Knocked down NOS›person
Pushed, pushing›by other person(s) (accidental)
Stepping on›person
Striking against›person(s)
Stumbling›over›person
Tripping›over›person
Accident›pedestrian›with›another pedestrian

Code to one of these instead W51

3 child codes. Green means billable.

Questions about W51

Is W51 a billable ICD-10-CM code?: No. W51 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does W51 sit in the tabular list?: External causes of morbidity (V00-Y99), in the block Exposure to animate mechanical forces (W50-W64).
What cannot be coded together with W51?: W51 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.