A84
Tick-borne viral encephalitis
A84 is a non-billable ICD-10-CM code category for tick-borne viral encephalitis. 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 A84.0 Far Eastern tick-borne encephalitis [Russian spring-summer encephalitis]; A84.1 Central European tick-borne encephalitis; A84.8 Other tick-borne viral encephalitis and A84.9 Tick-borne viral encephalitis, unspecified. Its coding notes include a Use additional code instruction, 3 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.
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.
- tick-borne viral meningoencephalitis
Also from chapter/block level (1 note)
- diseases generally recognized as communicable or transmissible