C37 vs C7A.091
C37 (Malignant neoplasm of thymus) compared with C7A.091 (Malignant carcinoid tumor of the thymus), 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. C37 carries an Excludes1 note covering C7A.091: “malignant carcinoid tumor of the thymus (C7A.091)”
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
| C37Malignant neoplasm of thymus | C7A.091Malignant carcinoid tumor of the thymus | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of thymus is a billable ICD-10-CM diagnosis code (C37). | Malignant carcinoid tumor of the thymus is a billable ICD-10-CM diagnosis code (C7A.091). |
| Includes | malignant neoplasm of middle ear | — |
| Use additional code | — | code to identify any associated endocrine syndrome, such as: carcinoid syndrome (E34.00) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources