A86 – Unspecified viral encephalitis

ICD-10-CM 2027 diagnosis code · Viral and prion infections of the central nervous system

Billable code

ICD-10-CM code A86
Code
A86 (claims format: A86)
Description
Unspecified viral encephalitis
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
1. Certain infectious and parasitic diseases (A00-B99)
Block
A80-A89 Viral and prion infections of the central nervous system

Notes for A86

Applicable to:
  • Viral encephalomyelitis NOS
  • Viral meningoencephalitis NOS

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block A80-A89

Excludes1 (not coded here):
  • postpolio syndrome (G14)
  • sequelae of poliomyelitis (B91)
  • sequelae of viral encephalitis (B94.1)

Index terms for A86

Entries in the ICD-10-CM alphabetic index that lead to this code:

Frequently asked questions

What is ICD-10 code A86?

A86 is the ICD-10-CM code for unspecified viral encephalitis, in the block A80-A89 (Viral and prion infections of the central nervous system).

Is A86 a billable code?

Yes. A86 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.