C38.1 Malignant neoplasm of anterior mediastinum

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

Applies from C38 Malignant neoplasm of heart, mediastinum and pleura

Excludes1 (never code together)

• mesothelioma (C45.-)

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) 180-182 in MDC 04.

Approximate ICD-9-CM (GEMs)

• 164.2 Malignant neoplasm of anterior mediastinum

Code annotations containing back-references to C38.1

Back-references to C38.1

• Type 1 Excludes: C49.3 Malignant neoplasm of connective and soft tissue of thorax ("malignant neoplasm of mediastinum (C38.1-C38.3)")

Nearby codes

• C38 Malignant neoplasm of heart, mediastinum and pleura
• C38.0 Malignant neoplasm of heart
• C38.1 Malignant neoplasm of anterior mediastinum (this code)
• C38.2 Malignant neoplasm of posterior mediastinum
• C38.3 Malignant neoplasm of mediastinum, part unspecified
• C38.4 Malignant neoplasm of pleura
• C38.8 Malignant neoplasm of overlapping sites of heart, mediastinum and pleura