C71.7 Malignant neoplasm of brain stem

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

Applicable to

• Malignant neoplasm of fourth cerebral ventricle
• Infratentorial malignant neoplasm NOS

Applies from C71 Malignant neoplasm of brain

Excludes1 (never code together)

• malignant neoplasm of cranial nerves (C72.2-C72.5)
• retrobulbar malignant neoplasm (C69.6-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 20 — Lung and Other Severe Cancers
• CMS-HCC V22: HCC 10 — Lymphoma and Other Cancers
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 10

MS-DRG index

Defines the logic of DRG(s) 054-055 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 191.7 Malignant neoplasm of brain stem

Code annotations containing back-references to C71.7

Back-references to C71.7

• Type 1 Excludes: C71.5 Malignant neoplasm of cerebral ventricle ("malignant neoplasm of fourth cerebral ventricle (C71.7)")

Nearby codes

• C71.2 Malignant neoplasm of temporal lobe
• C71.3 Malignant neoplasm of parietal lobe
• C71.4 Malignant neoplasm of occipital lobe
• C71.5 Malignant neoplasm of cerebral ventricle
• C71.6 Malignant neoplasm of cerebellum
• C71.7 Malignant neoplasm of brain stem (this code)
• C71.8 Malignant neoplasm of overlapping sites of brain
• C71.9 Malignant neoplasm of brain, unspecified