2020 ICD-10-CM Diagnosis Code A84

Tick-borne viral encephalitis

    2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
  • A84 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2020 edition of ICD-10-CM A84 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of A84 - other international versions of ICD-10 A84 may differ.
Includes
Includes Help
"Includes" further defines, or give examples of, the content of the code or category.
  • tick-borne viral meningoencephalitis
The following code(s) above A84 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to A84:
  • A00-B99
    2020 ICD-10-CM Range A00-B99

    Certain infectious and parasitic diseases

    Includes
    • diseases generally recognized as communicable or transmissible
    Type 1 Excludes
    • certain localized infections - see body system-related chapters
    Type 2 Excludes
    • carrier or suspected carrier of infectious disease (Z22.-)
    • 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)
    Use Additional
    • code to identify resistance to antimicrobial drugs (Z16.-)
    Certain infectious and parasitic diseases
  • A80-A89
    2020 ICD-10-CM Range A80-A89

    Viral and prion infections of the central nervous system

    Type 1 Excludes
    • postpolio syndrome (G14)
    • sequelae of poliomyelitis (B91)
    • sequelae of viral encephalitis (B94.1)
    Viral and prion infections of the central nervous system
Clinical Information
  • Encephalitis caused by neurotropic viruses that are transmitted via the bite of ticks. In europe, the diseases are caused by encephalitis viruses, tick-borne, which give rise to russian spring-summer encephalitis, central european encephalitis, louping ill encephalitis, and related disorders. Powassan encephalitis occurs in north america and russia and is caused by the powassan virus. Aseptic meningitis and rarely encephalitis may complicate colorado tick fever which is endemic to mountainous regions of the western United States. (from Joynt, Clinical Neurology, 1996, ch26, pp14-5)
Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
ICD-10-CM Codes Adjacent To A84
A83 Mosquito-borne viral encephalitis
A83.0 Japanese encephalitis
A83.1 Western equine encephalitis
A83.2 Eastern equine encephalitis
A83.3 St Louis encephalitis
A83.4 Australian encephalitis
A83.5 California encephalitis
A83.6 Rocio virus disease
A83.8 Other mosquito-borne viral encephalitis
A83.9 Mosquito-borne viral encephalitis, unspecified
A84 Tick-borne viral encephalitis
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
A84.9 Tick-borne viral encephalitis, unspecified
A85 Other viral encephalitis, not elsewhere classified
A85.0 Enteroviral encephalitis
A85.1 Adenoviral encephalitis
A85.2 Arthropod-borne viral encephalitis, unspecified
A85.8 Other specified viral encephalitis
A86 Unspecified viral encephalitis

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.