C37 Malignant neoplasm of thymus

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Excludes1 (never code together)

• malignant carcinoid tumor of the thymus (C7A.091)

Applies from C37 Malignant neoplasm of thymus

Excludes1 (never code together)

• malignant carcinoid tumor of the thymus (C7A.091)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 21 — Lymphoma and Other Cancers
• CMS-HCC V22: HCC 11 — Colorectal, Bladder, and Other Cancers
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 11

MS-DRG index

Defines the logic of DRG(s) 826-828 in MDC 17.

Approximate ICD-9-CM (GEMs)

• 164.0 Malignant neoplasm of thymus

Code annotations containing back-references to C37

Back-references to C37

• Type 1 Excludes: C49.3 Malignant neoplasm of connective and soft tissue of thorax ("malignant neoplasm of thymus (C37)")
• Type 1 Excludes: C75 Malignant neoplasm of other endocrine glands and related structures ("malignant neoplasm of thymus (C37)")

Back-references to C37

• Type 1 Excludes: C49.3 Malignant neoplasm of connective and soft tissue of thorax ("malignant neoplasm of thymus (C37)")
• Type 1 Excludes: C75 Malignant neoplasm of other endocrine glands and related structures ("malignant neoplasm of thymus (C37)")

Diagnosis Index entries for C37

• Carcinoma (malignant) › thymic
• Thymoma › malignant
• Thymoma › metaplastic
• Thymoma › sclerosing
• Thymoma › type A
• Thymoma › type AB
• Thymoma › type B1
• Thymoma › type B2
• Thymoma › type B3

Nearby codes

• C37 Malignant neoplasm of thymus (this code)