ICD-10 Code B10.0 – Other human herpesvirus encephalitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B10.0 – Other human herpesvirus encephalitis
What it is
B10.0 identifies encephalitis caused by a human herpesvirus other than the more common coded forms. Use it when the record clearly documents herpesvirus-related brain inflammation.
Clinical signs
Clinical features vary; refer to documentation. Encephalitis is typically described with altered mental status, fever, seizures, headache, or focal neurologic findings, but the exact viral cause must be documented.
When to use this code
Use B10.0 when the provider documents encephalitis due to an “other” human herpesvirus and does not specify a different coded herpesvirus type. It also fits when the note confirms herpesvirus encephalitis but leaves the exact subtype unspecified. Check documentation if the record only says viral encephalitis.
Do not use for
Do not use this code for encephalitis from non-herpes viral causes or for herpesvirus infection without brain involvement. If the chart names a different specific herpesvirus code, use that instead.
Coding tip
Code the documented virus and encephalitis together only when the record supports both; otherwise, query for clarification.