Other viral encephalitis, not elsewhere classified (A85) ICD-10-CM
The A85 code range covers other viral encephalitis, not elsewhere classified with 5 ICD-10-CM diagnosis codes. 4 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- specified viral encephalomyelitis NEC
- specified viral meningoencephalitis NEC
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- 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
Codes in the A85 Range 5 codes · 4 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A85 range.
Encephalitis, Arbovirus
Infections of the brain caused by arthropod-borne viruses (i.e., arboviruses) primarily from the families TOGAVIRIDAE; FLAVIVIRIDAE; BUNYAVIRIDAE; REOVIRIDAE; and RHABDOVIRIDAE. Life cycles of these viruses are characterized by ZOONOSES, with birds and lower mammals serving as intermediate hosts. The virus is transmitted to humans by the bite of mosquitoes (CULICIDAE) or TICKS. Clinical manifestations include fever, headache, alterations of mentation, focal neurologic deficits, and COMA. (From Clin Microbiol Rev 1994 Jan;7(1):89-116; Walton, Brain's Diseases of the Nervous System, 10th ed, p321)
About the A85 Code Range
These are viral infections of the central nervous system grouped as other viral encephalitis.
The subdivisions distinguish enteroviral encephalitis (A85.0), adenoviral encephalitis (A85.1), unspecified arthropod-borne viral encephalitis (A85.2), and other specified viral encephalitis (A85.8).
Questions About This Page
How many billable codes are in the A85 range?
Of the 5 codes in this range, 4 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the A85 range classify?
The range classifies other viral encephalitis, not elsewhere classified. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
