W40.9XXA — Explosion of unspecified explosive materials, initial encounter
Is W40.9XXA billable?
Yes, but W40.9XXA is an unspecified code. W40.9XXA is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, W40.9XXA is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting W40.9XXA — the more specific alternatives are listed below.
W40.9XXA at a glance
| Code | W40.9XXA |
|---|---|
| Description | Explosion of unspecified explosive materials, initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in W40.9XXA?
In W40.9XXA, the 7th character A means initial encounter. The 7th character is required for W40.9XXA to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
How is W40.9XXA listed in the External Cause Index?
The External Cause of Injuries Index lists these routes under W40.9, the nearest indexed parent of W40.9XXA. This is a separate index from the Alphabetic Index and is where external cause codes are looked up.
- Explosion (accidental) (of) (with secondary fire)
- Explosion › explosive (accidental) (of) (with secondary fire)
- Explosion › stove (accidental) (of) (with secondary fire)
- Poisoning › fumes or smoke due to › explosion (accidental) (by)
Inclusion terms
Alternative wording in documentation that is classified to W40.9XXA.
- Explosion NOS
Excludes1 — never code together — inherited from W20-W49
The conditions below can never be reported together with W40.9XXA on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes1 — never code together — inherited from W40
The conditions below can never be reported together with W40.9XXA on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
How long has W40.9XXA existed?
W40.9XXA has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.