ICD-10 Code G04.81 – Other encephalitis and encephalomyelitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G04.81 – Other encephalitis and encephalomyelitis
What it is
G04.81 identifies inflammatory disease affecting the brain, spinal cord, or both when the condition is classified as other encephalitis or encephalomyelitis. Use it for documented noninfectious or unspecified inflammatory neurologic syndromes that do not fit a more specific code.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings may include altered mental status, seizures, focal neurologic deficits, weakness, or signs of spinal cord involvement such as sensory changes or gait disturbance.
When to use this code
Use this code when the provider documents encephalitis, encephalomyelitis, or a similar inflammatory CNS disorder and no more specific etiology or subtype is stated. It is appropriate when the record supports brain and/or spinal cord inflammation but does not identify a better-defined diagnosis. Check documentation if infection, demyelinating disease, or another cause is named.
Do not use for
Do not use this code for infectious encephalitis when a causative organism is documented, or for demyelinating disorders such as multiple sclerosis. If the note describes another specific neurologic diagnosis, code that condition instead.
Coding tip
Confirm the exact provider wording and look for a documented cause before assigning G04.81.