D33.1 Benign neoplasm of brain, infratentorial

Billable ICD-10-CM code, FY2026.

Applicable to

• Benign neoplasm of brain stem
• Benign neoplasm of cerebellum
• Benign neoplasm of fourth ventricle

Applies from D33 Benign neoplasm of brain and other parts of central nervous system

Excludes1 (never code together)

• angioma (D18.0-)
• benign neoplasm of meninges (D32.-)
• benign neoplasm of peripheral nerves and autonomic nervous system (D36.1-)
• hemangioma (D18.0-)
• neurofibromatosis (Q85.0-)
• retro-ocular benign neoplasm (D31.6-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 23 — Prostate, Breast, and Other Cancers and Tumors
• CMS-HCC V22: HCC 12 — Breast, Prostate, and Other Cancers and Tumors
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 12

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 225.0 Benign neoplasm of brain (approximate)

Code annotations containing back-references to D33.1

Back-references to D33.1

• Type 1 Excludes: D33.0 Benign neoplasm of brain, supratentorial ("benign neoplasm of fourth ventricle (D33.1)")

Diagnosis Index entries for D33.1

• Papilloma › choroid plexus (lateral ventricle) (third ventricle) › fourth ventricle

Nearby codes

• D33 Benign neoplasm of brain and other parts of central nervous system
• D33.0 Benign neoplasm of brain, supratentorial
• D33.1 Benign neoplasm of brain, infratentorial (this code)
• D33.2 Benign neoplasm of brain, unspecified
• D33.3 Benign neoplasm of cranial nerves
• D33.4 Benign neoplasm of spinal cord
• D33.7 Benign neoplasm of other specified parts of central nervous system
• D33.9 Benign neoplasm of central nervous system, unspecified