Coding and coverage · ICD-10-CM
A85 Other viral encephalitis, not elsewhere classified
Report one of the more specific codes below.
Codes under this one
Instructional notes
Chapter 1
Excludes2Not included here: the patient may have both; report both when both are present.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Use additional codeAdd a second code for the full picture.
- code to identify resistance to antimicrobial drugs (Z16.-)
Includes
- diseases generally recognized as communicable or transmissible
Section A80-A89
This code
Excludes1Not coded here: never report with this code, except when the two conditions are unrelated.
- 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)
Includes
- specified viral encephalomyelitis NEC
- specified viral meningoencephalitis NEC
Chapter 1: Certain infectious and parasitic diseases · A80-A89 Viral and prion infections of the central nervous system (A80-A89)
Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.
Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.