ICD-10 Code B02.0 – Zoster encephalitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B02.0 – Zoster encephalitis
What it is
B02.0 identifies encephalitis caused by varicella-zoster virus. Use it when shingles infection involves the brain and is documented as zoster encephalitis.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include altered mental status, seizures, headache, fever, or focal neurologic deficits in the setting of zoster infection.
When to use this code
Use B02.0 when the provider documents encephalitis due to herpes zoster or zoster involvement of the central nervous system. The record should link the neurologic illness to zoster, not just mention a rash or prior shingles. If the diagnosis is uncertain, check documentation.
Do not use for
Do not use this code for uncomplicated shingles, postherpetic neuralgia, or other neurologic complications not documented as encephalitis. If encephalitis is due to another cause, use the appropriate code instead.
Coding tip
Confirm the provider explicitly connects encephalitis to zoster before assigning B02.0.