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ICD-10-CM 2027 diagnosis code

A84.8Other tick-borne viral encephalitis

Not billable — use a more specific code

A84.8 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.

Code last changed in FY2021 (effective October 1, 2020). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About A84.8

A84.8 is the ICD-10-CM diagnosis code for other tick-borne viral encephalitis. It belongs to category A84 (tick-borne viral encephalitis), block A80-A89 (viral and prion infections of the central nervous system) and chapter 1 (certain infectious and parasitic diseases). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within A84, choose A84.8 (Other tick-borne viral encephalitis) only when documentation doesn't support a more specific option: Far Eastern tick-borne encephalitis [Russian spring-summer encephalitis] (A84.0), central European tick-borne encephalitis (A84.1) and unspecified (A84.9).

To report this condition, pick the subcode that matches the documentation: A84.81 (disease) and A84.89 (encephalitis).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2021 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 063.1 (Louping ill) and 063.8 (other specified tick-borne viral encephalitis).

Specific codes under A84.8

Notes that apply from higher levels

Instructions written at a parent level also apply to A84.8.

› From A84 Tick-borne viral encephalitis
Includes
  • tick-borne viral meningoencephalitis

Broader instructions also apply from A80-A89 Viral and prion infections of the central nervous system and Chapter 1: Certain infectious and parasitic diseases.

ICD-9-CM equivalent

Converter →
  • 063.1Louping illapproximate
  • 063.8Other specified tick-borne viral encephalitisapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • FY2021 (effective 10/1/2020): Expanded — no longer billable

Common questions about A84.8

Is A84.8 billable?

No. A84.8 is a header code. Report one of its more specific subcodes instead.

What is the ICD-9 code for A84.8?

The CMS General Equivalence Mappings map A84.8 to ICD-9-CM 063.1 and 063.8.