Is X99.8 a billable ICD-10-CM code?

No. X99.8 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does X99.8 sit in the tabular list?

External causes of morbidity (V00-Y99), in the block Assault (X92-Y09).

What cannot be coded together with X99.8?

X99.8 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 X99.8 (X99) and apply to it just the same.

X99.8

X99.8 — Assault by other sharp object

Non-billable headerICD-10-CM

X99.8 is a non-billable header ICD-10-CM code for assault by other sharp object. 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 X99

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 inherited from the categories above X99.8

These are not written on X99.8, but they bind it: a note on a category applies to every code beneath it. Billing X99.8 with anything listed here is a denial.

Written on X99 — Assault by sharp object

assault by strike by sports equipment (Y08.0-)

Risk adjustment

X99.8 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 X99.8 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 X99.8.

Assault›cutting or piercing instrument›specified NEC

Code history

X99.8 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 X99.8

3 child codes. Green means billable.

Related codes at this level

Codes that share X99. If X99.8 is not quite right, the correct code is usually one of these.

Questions about X99.8

Is X99.8 a billable ICD-10-CM code?: No. X99.8 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does X99.8 sit in the tabular list?: External causes of morbidity (V00-Y99), in the block Assault (X92-Y09).
What cannot be coded together with X99.8?: X99.8 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 X99.8 (X99) and apply to it just the same.