2023 ICD-10-CM Diagnosis Code A85.8

Other specified viral encephalitis

    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  • A85.8 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2023 edition of ICD-10-CM A85.8 became effective on October 1, 2022.
  • This is the American ICD-10-CM version of A85.8 - other international versions of ICD-10 A85.8 may differ.
Applicable To
  • Encephalitis lethargica
  • Von Economo-Cruchet disease
The following code(s) above A85.8 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 A85.8:
  • A00-B99
    2023 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
    2023 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
  • A85
    ICD-10-CM Diagnosis Code A85

    Other viral encephalitis, not elsewhere classified

      2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
    Includes
    • specified viral encephalomyelitis NEC
    • specified viral meningoencephalitis NEC
    Type 1 Excludes
    • encephalitis due to cytomegalovirus (B25.8)
    • encephalitis due to herpesvirus NEC (B10.0-)
    • encephalitis due to herpesvirus [herpes simplex] (B00.4)
    • encephalitis due to measles virus (B05.0)
    • encephalitis due to mumps virus (B26.2)
    • encephalitis due to poliomyelitis virus (A80.-)
    • encephalitis due to zoster (B02.0)
    • lymphocytic choriomeningitis (A87.2)
    • myalgic encephalomyelitis (G93.32)
    Other viral encephalitis, not elsewhere classified
Approximate Synonyms
  • Encephalitis lethargica
ICD-10-CM A85.8 is grouped within Diagnostic Related Group(s) (MS-DRG v40.0):
  • 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
  • 974 Hiv with major related condition with mcc
  • 975 Hiv with major related condition with cc
  • 976 Hiv with major related condition without cc/mcc

Convert A85.8 to ICD-9-CM

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
  • 2021 (effective 10/1/2020): No change
  • 2022 (effective 10/1/2021): No change
  • 2023 (effective 10/1/2022): No change

Diagnosis Index entries containing back-references to A85.8:
  • Cruchet's disease A85.8
  • Economo's disease A85.8
  • Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) G04.90
    ICD-10-CM Diagnosis Code G04.90

    Encephalitis and encephalomyelitis, unspecified

      2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
    Applicable To
    • Ventriculitis (cerebral) NOS
    • acute A86
      - see also Encephalitis, viral
      ICD-10-CM Diagnosis Code A86

      Unspecified viral encephalitis

        2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
      Applicable To
      • Viral encephalomyelitis NOS
      • Viral meningoencephalitis NOS
      • inclusion body A85.8
    • viral, virus A86
      ICD-10-CM Diagnosis Code A86

      Unspecified viral encephalitis

        2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
      Applicable To
      • Viral encephalomyelitis NOS
      • Viral meningoencephalitis NOS
      • specified type NEC A85.8
    • lethargica A85.8 (acute) (infectious)
    • Mengo A85.8
    • Rio Bravo A85.8
    • Vienna A85.8
  • Von Economo-Cruchet disease A85.8

ICD-10-CM Codes Adjacent To A85.8
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
A84.81 Powassan virus disease
A84.89 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
A87 Viral meningitis
A87.0 Enteroviral meningitis
A87.1 Adenoviral meningitis
A87.2 Lymphocytic choriomeningitis
A87.8 Other viral meningitis
A87.9 Viral meningitis, unspecified
A88 Other viral infections of central nervous system, not elsewhere classified
A88.0 Enteroviral exanthematous fever [Boston exanthem]
A88.1 Epidemic vertigo

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