ICD-10 Code A83.0 – Japanese encephalitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A83.0 – Japanese encephalitis
What it is
Japanese encephalitis is a viral infection that causes inflammation of the brain. Use this code for confirmed Japanese encephalitis, not for nonspecific encephalitis or viral illness.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include fever, headache, altered mental status, seizures, or neurologic deficits consistent with encephalitis.
When to use this code
Use A83.0 when the provider documents Japanese encephalitis by name or clearly identifies the infection as the cause of encephalitis. It may also apply when the record confirms the diagnosis after evaluation of compatible neurologic illness. If documentation is uncertain, check documentation before coding.
Do not use for
Do not use this code for suspected encephalitis without confirmation, or for other viral encephalitides. Do not use it for meningitis alone or for exposure to Japanese encephalitis virus without disease.
Coding tip
Code the documented organism-specific diagnosis only when the record supports Japanese encephalitis, and query the provider if the encephalitis type is unclear.