ICD-10 Code C71.9 – Malignant neoplasm of brain, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C71.9 – Malignant neoplasm of brain, unspecified
What it is
C71.9 identifies a malignant tumor arising in the brain when the specific site is not documented. Use it for primary brain cancer that is confirmed but not further localized.
Clinical signs
Clinical features vary; refer to documentation. Common findings include neurological deficits, headaches, seizures, or signs of raised intracranial pressure, but the record should support a malignant brain neoplasm.
When to use this code
Use C71.9 when the provider documents a malignant neoplasm of the brain and does not specify the exact brain region. It also fits when the note confirms a primary brain malignancy but laterality or subsite is not stated. Check documentation if the diagnosis could instead be a metastatic lesion.
Do not use for
Do not use this code for benign brain tumors, tumors of the meninges, or metastatic disease to the brain. If the documentation names a specific brain site, code that more precise subcategory instead.
Coding tip
Query for the exact brain subsite whenever the record says only “brain tumor” or “brain mass.”