ICD-10 Code C71 – Malignant neoplasm of brain (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C71 – Malignant neoplasm of brain
What it is
C71 identifies a malignant tumor arising in the brain. Use it for documented primary brain cancer when the record specifies the brain but not a more exact site.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include progressive headaches, seizures, focal neurologic deficits, or signs of increased intracranial pressure.
When to use this code
Use C71 when the provider documents a malignant neoplasm of the brain and no more specific subsite is available. It also fits cases where pathology or imaging confirms a primary brain malignancy. If the record identifies a different CNS site, code that site instead.
Do not use for
Do not use C71 for benign brain tumors, metastatic disease to the brain, or nonspecific “brain mass” without malignant confirmation. Check documentation.
Coding tip
Code to the most specific brain subsite documented; if the chart is vague, query for clarification before assigning C71.