W90 vs Z77.123
W90 (Exposure to other nonionizing radiation) compared with Z77.123 (Contact with and (suspected) exposure to radon and other naturally occurring radiation), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. Z77.123 carries an Excludes2 note covering W90: “radiation exposure as the cause of a confirmed condition (W88-W90, X39.0-)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| W90Exposure to other nonionizing radiation | Z77.123Contact with and (suspected) exposure to radon and other naturally occurring radiation | |
|---|---|---|
| Billing status | Non-billable header Report instead: W90.0XXA, W90.0XXD, W90.0XXS, W90.1XXA, W90.1XXD | Billable |
| Classification | V00-Y99 — External Causes of Morbidity (V00-Y99) | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) |
| Definition | Exposure to other nonionizing radiation is a non-billable ICD-10-CM category code (W90). | Contact with and (suspected) exposure to radon and other naturally occurring radiation is a billable ICD-10-CM diagnosis code (Z77.123). |
| 7th character | The appropriate 7th character is to be added to each code from category W90 | — |
| Includes | — | contact with and (suspected) exposures to potential hazards to health |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources