2024 ICD-10-CM Diagnosis Code A84.9

by

Tick-borne viral encephalitis, unspecified

  • A84.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2024 edition of ICD-10-CM A84.9 became effective on October 1, 2023.
  • This is the American ICD-10-CM version of A84.9 – other international versions of ICD-10 A84.9 may differ.

The following code(s) above A84.9 contain annotation back-references

 that may be applicable to A84.9:

  • A00-B99  Certain infectious and parasitic diseases
  • A80-A89  Viral and prion infections of the central nervous system
  • A84  Tick-borne viral encephalitis

Approximate Synonyms

  • Tick-borne viral encephalitis
  • Viral encephalitis, tick borne

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)

ICD-10-CM A84.9 is grouped within Diagnostic Related Group(s) (MS-DRG v41.0):

  • 023 Craniotomy with major device implant or acute complex cns principal diagnosis with mcc or chemotherapy implant or epilepsy with neurostimulator
  • 024 Craniotomy with major device implant or acute complex cns principal diagnosis without mcc
  • 097 Non-bacterial infection of nervous system except viral meningitis with mcc
  • 098 Non-bacterial infection of nervous system except viral meningitis with cc
  • 099 Non-bacterial infection of nervous system except viral meningitis without cc/mcc

Convert A84.9 to ICD-9-CMCode 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
  • 2021 (effective 10/1/2020): No change
  • 2022 (effective 10/1/2021): No change
  • 2023 (effective 10/1/2022): No change
  • 2024 (effective 10/1/2023): No change

Diagnosis Index entries containing back-references to A84.9: