C37 vs C49.3
C37 (Malignant neoplasm of thymus) compared with C49.3 (Malignant neoplasm of connective and soft tissue of thorax), 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. C49.3 carries an Excludes1 note covering C37: “malignant neoplasm of thymus (C37)”
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 | C49.3Malignant neoplasm of connective and soft tissue of thorax | |
|---|---|---|
| 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 neoplasm of connective and soft tissue of thorax is a billable ICD-10-CM diagnosis code (C49.3). |
| Includes | malignant neoplasm of middle ear | malignant neoplasm of blood vessel malignant neoplasm of bursa malignant neoplasm of cartilage malignant neoplasm of fascia |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources