2026 ICD-10-CM Diagnosis Code C71.5Malignant neoplasm of cerebral ventricle

ICD-10-CM CodesC00–D49C69-C72C71

ICD-10-CM C71.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C71.5 is a billable ICD-10-CM diagnosis code for malignant neoplasm of cerebral ventricle. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system cancers - brain.

Code Identity

ICD-10-CM Code
C71.5
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of cerebral ventricle
Short Description
Malignant neoplasm of cerebral ventricle
Same as the full description in the CMS dataset.
Parent Code
Malignant neoplasm of brain

Code Classification

ChapterC00–D49Neoplasms
SectionC69-C72Malignant neoplasms of eye, brain and other parts of central nervous system
CategoryC71Malignant neoplasm of brain
This CodeC71.5Malignant neoplasm of cerebral ventricle

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Choroid plexus carcinoma
  • Increased cerebrospinal fluid production
  • Increased cerebrospinal fluid production due to choroid plexus carcinoma
  • Malignant neoplasm of choroid plexus
  • Malignant neoplasm of floor of cerebral ventricle
  • Malignant neoplasm of ventricle of brain
  • Neoplasm of choroid plexus
  • Primary astrocytoma of cerebral ventricle
  • Primary choroid plexus carcinoma
  • Primary ependymoma of brain ventricle
  • Primary glioblastoma multiforme of brain
  • Primary glioblastoma multiforme of cerebral ventricle
  • Primary malignant astrocytoma of brain
  • Primary malignant glioma of cerebral ventricle
  • Primary malignant neoplasm of brain ventricle

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • malignant neoplasm of fourth cerebral ventricle C71.7

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Papilloma
      • choroid plexus (lateral ventricle) (third ventricle)
        • anaplastic
    • Papilloma
      • choroid plexus (lateral ventricle) (third ventricle)
        • malignant

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO048
Nervous system cancers - brain
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
brain NEC ventricle (floor)C71.5C79.31D33.0D43.0D49.6
cerebrum, cerebral (cortex) (hemisphere) (white matter) ventricleC71.5C79.31D33.0D43.0D49.6
choroid plexusC71.5C79.31D33.0D43.0D49.6
ependyma (brain)C71.5C79.31D33.0D43.0D49.6
plexus choroidC71.5C79.31D33.0D43.0D49.6
ventricle (cerebral) (floor) (lateral) (third)C71.5C79.31D33.0D43.0D49.6

Patient EducationClinical

Brain Tumors

A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, or malignant, with cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are metastatic, and they start somewhere else in the body and move to the brain.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C71.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
191.5 Mal neo cereb ventricle
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C71.5Overview

Is C71.5 (Malignant neoplasm of brain) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of cerebral ventricle on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of C71.5?

Under the General Equivalence Mappings, malignant neoplasm of cerebral ventricle converts to ICD-9-CM 191.5 (mal neo cereb ventricle). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.