C37 is the authoritative medical code for Malignant neoplasm of thymus. This classification is used in medical billing and clinical recording to specify the clinical criteria for malignant neoplasm of thymus (ICD-10-CM C37), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Malignant neoplasm of thymus is a billable ICD-10-CM diagnosis code C37. Includes: malignant neoplasm of middle ear. Excludes1 (not coded here): malignant carcinoid tumor of the thymus C7A.091; mesothelioma C45.-.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for C37 in the official ICD-10-CM tabular list.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- malignant neoplasm of middle ear
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- malignant carcinoid tumor of the thymus C7A.091
- mesothelioma C45.-
Frequently Asked Questions (FAQ) & Clinical Guidance
What can't be coded together with C37?
Per Excludes1 instructions, C37 must not be reported with: malignant carcinoid tumor of the thymus (C7A.091); mesothelioma (C45.-).
Indexed Clinical Terms (9)
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.
- Carcinoma (malignant), thymic
- Thymoma, malignant
- Thymoma, metaplastic
- Thymoma, sclerosing
- Thymoma, type A
- Thymoma, type AB
- Thymoma, type B1
- Thymoma, type B2
- Thymoma, type B3
Neoplasm Table Sites (1)
Anatomical sites from the official ICD-10-CM Table of Neoplasms that map to this code, with the matching behavior column.
- Neoplasm, neoplastic, thymus (gland) — Malignant, Primary
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:
ICD Code C38
Malignant neoplasm of heart, mediastinum and pleura
ICD Code C39
Malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs
ICD Code C40
Malignant neoplasm of bone and articular cartilage of limbs
ICD Code C41
Malignant neoplasm of bone and articular cartilage of other and unspecified sites