A85
Other viral encephalitis, not elsewhere classified
A85 is a non-billable ICD-10-CM code category for other viral encephalitis, not elsewhere classified. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are A85.0 Enteroviral encephalitis; A85.1 Adenoviral encephalitis; A85.2 Arthropod-borne viral encephalitis, unspecified and A85.8 Other specified viral encephalitis. Its coding notes include a Use additional code instruction, 12 Excludes1 entries and 5 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- 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)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (5 notes)
- 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)
Includes
Further defines or gives examples of the content of the category.
- specified viral encephalomyelitis NEC
- specified viral meningoencephalitis NEC
Also from chapter/block level (1 note)
- diseases generally recognized as communicable or transmissible