A86
Billable codeUnspecified 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.
- •This code describes an unspecified presentation. If the medical record documents a more specific detail (e.g. laterality, type, or affected site), a more specific sibling code should be used instead — see Related codes below.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- A80Acute poliomyelitisnon-billable header
- A81Atypical virus infections of central nervous systemnon-billable header
- A82Rabiesnon-billable header
- A83Mosquito-borne viral encephalitisnon-billable header
- A84Tick-borne viral encephalitisnon-billable header
- A85Other viral encephalitis, not elsewhere classifiednon-billable header
- A87Viral meningitisnon-billable header
- A88Other viral infections of central nervous system, not elsewhere classifiednon-billable header
- A89Unspecified viral infection of central nervous system
- A86Unspecified viral encephalitis
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 0499Approximate match
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.