W94 vs X30
W94 (Exposure to high and low air pressure and changes in air pressure) compared with X30 (Exposure to excessive natural heat), 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. W94 carries an Excludes1 note covering X30: “natural heat (X30)”
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
| W94Exposure to high and low air pressure and changes in air pressure | X30Exposure to excessive natural heat | |
|---|---|---|
| Billing status | Non-billable header Report instead: W94.0XXA, W94.0XXD, W94.0XXS, W94.11XA, W94.11XD | Non-billable header |
| Classification | V00-Y99 — External Causes of Morbidity (V00-Y99) | V00-Y99 — External Causes of Morbidity (V00-Y99) |
| Definition | Exposure to high and low air pressure and changes in air pressure is a non-billable ICD-10-CM category code (W94). | Exposure to excessive natural heat is a non-billable ICD-10-CM category code (X30). |
| 7th character | The appropriate 7th character is to be added to each code from category W94 | The appropriate 7th character is to be added to code X30 |
| Includes | — | Exposure to excessive heat as the cause of sunstroke Exposure to heat NOS |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources