A85 – Other viral encephalitis, not elsewhere classified

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

Non-billable header

ICD-10-CM code A85
Code
A85 (claims format: A85)
Description
Other viral encephalitis, not elsewhere classified
Billable
No – use a more specific code below
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

Billable codes under A85

A85 is a header code and cannot be used on claims. Choose the most specific code:

Notes for A85

Includes:
  • specified viral encephalomyelitis NEC
  • specified viral meningoencephalitis NEC
Excludes1 (not coded here):
  • encephalitis due to cytomegalovirus (B25.8)
  • encephalitis due to herpesvirus NEC (B10.0-)
  • encephalitis due to herpesvirus [herpes simplex] (B00.4)
  • encephalitis due to measles virus (B05.0)
  • encephalitis due to mumps virus (B26.2)
  • encephalitis due to poliomyelitis virus (A80.-)
  • encephalitis due to zoster (B02.0)
  • lymphocytic choriomeningitis (A87.2)
  • myalgic encephalomyelitis (G93.32)

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)

Frequently asked questions

What is ICD-10 code A85?

A85 is the ICD-10-CM code for other viral encephalitis, not elsewhere classified, in the block A80-A89 (Viral and prion infections of the central nervous system).

Is A85 a billable code?

No. A85 is a header code with more specific child codes; report one of the billable codes listed above.

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.