W40 vs Y09
W40 (Explosion of other materials) compared with Y09 (Assault by unspecified means), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. W40 carries an Excludes1 note covering Y09: “assault (X92-Y09)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| W40Explosion of other materials | Y09Assault by unspecified means | |
|---|---|---|
| Billing status | Non-billable header Report instead: W40.0XXA, W40.0XXD, W40.0XXS, W40.1XXA, W40.1XXD | Billable |
| Classification | V00-Y99 — External Causes of Morbidity (V00-Y99) | V00-Y99 — External Causes of Morbidity (V00-Y99) |
| Definition | Explosion of other materials is a non-billable ICD-10-CM category code (W40). | Assault by unspecified means is a billable ICD-10-CM diagnosis code (Y09). |
| 7th character | The appropriate 7th character is to be added to each code from category W40 | — |
| Includes | — | homicide injuries inflicted by another person with intent to injure or kill, by any means Assassination (attempted) NOS Homicide (attempted) NOS |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources