W99 – Exposure to other man-made environmental factors
ICD-10-CM 2027 diagnosis code · Exposure to electric current, radiation and extreme ambient air temperature and pressure
- Code
W99(claims format:W99)- Description
- Exposure to other man-made environmental factors
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 20. External causes of morbidity (V00-Y99)
- Block
- W85-W99 Exposure to electric current, radiation and extreme ambient air temperature and pressure
Billable codes under W99
W99 is a header code and cannot be used on claims. Choose the most specific code:
7th character values
Codes in this category need a 7th character to describe the encounter or episode of care (use placeholder X for empty positions).
| Character | Meaning |
|---|---|
A | initial encounter |
D | subsequent encounter |
S | sequela |
Notes for W99
- The appropriate 7th character is to be added to code W99
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
Block W85-W99
Frequently asked questions
What is ICD-10 code W99?
W99 is the ICD-10-CM code for exposure to other man-made environmental factors, in the block W85-W99 (Exposure to electric current, radiation and extreme ambient air temperature and pressure).
Is W99 a billable code?
No. W99 is a header code with more specific child codes; report one of the billable codes listed above.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.