C33 vs C45
C33 (Malignant neoplasm of trachea) compared with C45 (Mesothelioma), 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. C33 carries an Excludes1 note covering C45: “mesothelioma (C45.-)”
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
| C33Malignant neoplasm of trachea | C45Mesothelioma | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of trachea is a billable ICD-10-CM diagnosis code (C33). | Mesothelioma is a non-billable ICD-10-CM category code (C45). |
| Includes | malignant neoplasm of middle ear | — |
| Use additional code | code to identify: exposure to environmental tobacco smoke (Z77.22) exposure to tobacco smoke in the perinatal period (P96.81) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources