Tick-borne viral encephalitis (A84) ICD-10-CM
The A84 code range covers tick-borne viral encephalitis with 7 ICD-10-CM diagnosis codes. 5 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.
- tick-borne viral meningoencephalitis
Codes in the A84 Range 7 codes · 5 billable
- A84 Tick-borne viral encephalitisNon-billable
- A84.0 Far Eastern tick-borne encephalitis [Russian spring-summer encephalitis]
- A84.1 Central European tick-borne encephalitis
- A84.8 Other tick-borne viral encephalitisNon-billable
- A84.81 Powassan virus disease
- A84.89 Other tick-borne viral encephalitis
- A84.9 Tick-borne viral encephalitis, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A84 range.
Louping Ill
An acute tick-borne arbovirus infection causing meningoencephalomyelitis of sheep.
Tick-Borne Viral Encephalitis
Viral encephalitis that is transmitted by ticks.
About the A84 Code Range
Tick-borne viral encephalitis is brain inflammation caused by a virus transmitted by ticks.
The subdivisions distinguish Far Eastern A84.0 and Central European A84.1 forms from other A84.8 and unspecified A84.9 forms. Within the other-forms branch, A84.81 identifies Powassan virus disease, while A84.89 identifies other tick-borne viral encephalitis.
Questions About This Page
How many billable codes are in the A84 range?
Of the 7 codes in this range, 5 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 A84 range classify?
The range classifies tick-borne viral encephalitis. 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.
