W99
W99 — Exposure to other man-made environmental factors
Non-billable headerICD-10-CM
W99 is a non-billable header ICD-10-CM code for exposure to other man-made environmental factors. 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 W99
- A
- initial encounter
- D
- subsequent encounter
- S
- sequela
Risk adjustment
W99 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 W99 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 W99.
- Exposure›factor NOS›environmental NEC›man-made NEC
Code to one of these instead W99
3 child codes. Green means billable.
Questions about W99
- Is W99 a billable ICD-10-CM code?
- No. W99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
- Where does W99 sit in the tabular list?
- External causes of morbidity (V00-Y99), in the block Exposure to electric current, radiation and extreme ambient air temperature and pressure (W85-W99).