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  6. 2026 ICD-10-CM Code C71.1

2026 ICD-10-CM Diagnosis Code C71.1

Malignant neoplasm of frontal lobe

ICD-10-CM Code:
C71.1
ICD-10 Code for:
Malignant neoplasm of frontal lobe
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

C71.1 is a billable diagnosis code used to specify a medical diagnosis of malignant neoplasm of frontal lobe. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

The following anatomical sites found in the Table of Neoplasms reference this diagnosis code given the correct histological behavior: Neoplasm, neoplastic brain NEC frontal lobe or Neoplasm, neoplastic frontal lobe, brain or Neoplasm, neoplastic frontal pole or Neoplasm, neoplastic pole or Neoplasm, neoplastic pole frontal .

Code Classification

  • Neoplasms
    C00–D49
    • Malignant neoplasms of eye, brain and other parts of central nervous system
      C69-C72
      • Malignant neoplasm of brain
        C71

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • 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 Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Nervous system cancers - brain

CCSR Code: NEO048

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Convert C71.1 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Malig neo frontal lobe

ICD-9-CM: 191.1

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

View Conversion

Table of Neoplasms

This code is referenced in the table of neoplasms by anatomical site. For each site there are six possible code numbers according to whether the neoplasm in question is malignant, benign, in situ, of uncertain behavior, or of unspecified nature. The description of the neoplasm will often indicate which of the six columns is appropriate.

Where such descriptors are not present, the remainder of the Index should be consulted where guidance is given to the appropriate column for each morphological (histological) variety listed. However, the guidance in the Index can be overridden if one of the descriptors mentioned above is present.

Neoplasm, neoplastic Malignant
Primary		 Malignant
Secondary		 CaInSitu Benign Uncertain
Behavior		 Unspecified
Behavior
»Neoplasm, neoplastic
  »brain NEC
    »frontal lobe
C71.1C79.31 D33.0D43.0D49.6
»Neoplasm, neoplastic
  »frontal
    »lobe, brain
C71.1C79.31 D33.0D43.0D49.6
»Neoplasm, neoplastic
  »frontal
    »pole
C71.1C79.31 D33.0D43.0D49.6
»Neoplasm, neoplastic
  »pole
C71.1C79.31 D33.0D43.0D49.6
»Neoplasm, neoplastic
  »pole
    »frontal
C71.1C79.31 D33.0D43.0D49.6

Patient Education


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.

Brain tumors can cause many symptoms. Some of the most common are:

  • Headaches, often in the morning
  • Nausea and vomiting
  • Changes in your ability to talk, hear, or see
  • Problems with balance or walking
  • Problems with thinking or memory
  • Feeling weak or sleepy
  • Changes in your mood or behavior
  • Seizures

Doctors diagnose brain tumors by doing a neurologic exam and tests including an MRI, CT scan, and biopsy. Treatment options include watchful waiting, surgery, radiation therapy, chemotherapy, and targeted therapy. Targeted therapy uses drugs or other substances that attack cancer cells with less harm to normal cells. Many people get a combination of treatments.

NIH: National Cancer Institute


[Learn More in MedlinePlus]

Brain Tumors-Patient Version

Learn about brain and spinal cord tumor risk factors, symptoms, tests to diagnose, factors affecting prognosis, and treatment.
[Learn More in MedlinePlus]

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

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.