Is W31 a billable ICD-10-CM code?

No. W31 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does W31 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 W31?

W31 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

W31

W31 — Contact with other and unspecified machinery

Non-billable headerICD-10-CM

W31 is a non-billable header ICD-10-CM code for contact with other and unspecified machinery. 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 W31

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.

contact with agricultural machinery (W30.-)
contact with machinery in transport under own power or being towed by a vehicle (V01-V99)
exposure to electric current (W86)

Other codes that can never be billed with W31

These codes carry an Excludes1 note pointing at W31. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading W31 alone.

V83Occupant of special vehicle mainly used on industrial premises injured in transport accident
V85Occupant of special construction vehicle injured in transport accident
V86Occupant of special all-terrain or other off-road motor vehicle, injured in transport accident
W09Fall on and from playground equipment
W20Struck by thrown, projected or falling object
W23Caught, crushed, jammed or pinched in or between objects
W29Contact with other powered hand tools and household machinery

Risk adjustment

W31 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 to one of these instead W31

6 child codes. Green means billable.

Questions about W31

Is W31 a billable ICD-10-CM code?: No. W31 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does W31 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 W31?: W31 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.