2026 ICD-10-CM Diagnosis Code C71.1Malignant neoplasm of frontal lobe

ICD-10-CM Codes›C00–D49›C69-C72›C71

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

C71.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of frontal lobe. 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
C71.1
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of frontal lobe
Short Description
Malignant neoplasm of frontal lobe
Same as the full description in the CMS dataset.
Parent Code
C71
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 CodeC71.1Malignant neoplasm of frontal lobe

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Anaplastic astrocytoma of brain
  • Anaplastic astrocytoma of central nervous system
  • Astrocytoma of cerebrum
  • Ependymoma of cerebrum
  • Malignant neoplasm of frontal lobe
  • Oligodendroglioma of brain
  • Oligodendroglioma of cerebrum
  • Primary anaplastic astrocytoma of brain
  • Primary anaplastic astrocytoma of central nervous system
  • Primary anaplastic astrocytoma of cerebrum
  • Primary anaplastic astrocytoma of frontal lobe
  • Primary astrocytoma of cerebrum
  • Primary astrocytoma of frontal lobe
  • Primary ependymoma of frontal lobe
  • Primary glioblastoma multiforme of brain
  • Primary glioblastoma multiforme of cerebrum
  • Primary glioblastoma multiforme of frontal lobe
  • Primary malignant astrocytoma of brain
  • Primary malignant glioma of frontal lobe
  • Primary malignant neoplasm of frontal lobe
  • Primary oligodendroglioma
  • Primary oligodendroglioma of brain
  • Primary oligodendroglioma of cerebrum
  • Primary oligodendroglioma of frontal lobe

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 › frontal lobeC71.1C79.31–D33.0D43.0D49.6
frontal › lobe, brainC71.1C79.31–D33.0D43.0D49.6
frontal › poleC71.1C79.31–D33.0D43.0D49.6
poleC71.1C79.31–D33.0D43.0D49.6
pole › frontalC71.1C79.31–D33.0D43.0D49.6

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 C71.1 to ICD-9-CMHistory

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

ICD-9-CM
191.1 Malig neo frontal lobe
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 C71.1Overview

Is C71.1 (Malignant neoplasm of brain) a billable code?

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

What is the ICD-9 equivalent of C71.1?

Under the General Equivalence Mappings, malignant neoplasm of frontal lobe converts to ICD-9-CM 191.1 (malig neo frontal lobe). 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.