10ICD Code Hub

A86

Billable code

Unspecified viral encephalitis

The ICD-10 code for unspecified viral encephalitis is A86.

Clinical notes

Also known as

Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.

  • Viral encephalomyelitis NOS
  • Viral meningoencephalitis NOS

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

Related codes in this category

ICD-9-CM equivalent

Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.

View full ICD-10 → ICD-9 crosswalk →

Associated MS-DRGs

A86 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.

Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.