A83.5 California encephalitis

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applicable to

• California meningoencephalitis
• La Crosse encephalitis

Applies from A83 Mosquito-borne viral encephalitis

Includes

• mosquito-borne viral meningoencephalitis

Excludes2 (not included here)

• Venezuelan equine encephalitis (A92.2)
• West Nile fever (A92.3-)
• West Nile virus (A92.3-)

MS-DRG index

Defines the logic of DRG(s) 023-024 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 062.5 California virus encephalitis

Diagnosis Index entries for A83.5

• California › encephalitis
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › California (virus)
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › La Crosse
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › mosquito-borne › California virus
• Meningoencephalitis › California

Nearby codes

• A83.0 Japanese encephalitis
• A83.1 Western equine encephalitis
• A83.2 Eastern equine encephalitis
• A83.3 St Louis encephalitis
• A83.4 Australian encephalitis
• A83.5 California encephalitis (this code)
• A83.6 Rocio virus disease
• A83.8 Other mosquito-borne viral encephalitis
• A83.9 Mosquito-borne viral encephalitis, unspecified