2023 ICD-10-CM Diagnosis Code G04.91

Myelitis, unspecified

    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  • G04.91 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 G04.91 became effective on October 1, 2022.
  • This is the American ICD-10-CM version of G04.91 - other international versions of ICD-10 G04.91 may differ.
The following code(s) above G04.91 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 G04.91:
  • G00-G99
    2023 ICD-10-CM Range G00-G99

    Diseases of the nervous system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the nervous system
  • G04
    ICD-10-CM Diagnosis Code G04

    Encephalitis, myelitis and encephalomyelitis

      2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
    Includes
    • acute ascending myelitis
    • meningoencephalitis
    • meningomyelitis
    Type 1 Excludes
    Type 2 Excludes
    • acute transverse myelitis (G37.3-)
    • alcoholic encephalopathy (G31.2)
    • multiple sclerosis (G35)
    • myalgic encephalomyelitis (G93.32)
    • subacute necrotizing myelitis (G37.4)
    • toxic encephalitis (G92.8)
    • toxic encephalopathy (G92.8)
    Encephalitis, myelitis and encephalomyelitis
Approximate Synonyms
  • Myelitis
ICD-10-CM G04.91 is grouped within Diagnostic Related Group(s) (MS-DRG v40.0):
  • 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
  • 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 G04.91 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 G04.91:
  • Infection, infected, infective (opportunistic) B99.9
    ICD-10-CM Diagnosis Code B99.9

    Unspecified infectious disease

      2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  • Myelitis (acute) (ascending) (childhood) (chronic) (descending) (diffuse) (disseminated) (idiopathic) (pressure) (progressive) (spinal cord) (subacute) G04.91 - see also Encephalitis
  • Myeloradiculitis G04.91

ICD-10-CM Codes Adjacent To G04.91
G04.30 …… unspecified
G04.31 Postinfectious acute necrotizing hemorrhagic encephalopathy
G04.32 Postimmunization acute necrotizing hemorrhagic encephalopathy
G04.39 Other acute necrotizing hemorrhagic encephalopathy
G04.8 Other encephalitis, myelitis and encephalomyelitis
G04.81 Other encephalitis and encephalomyelitis
G04.82 Acute flaccid myelitis
G04.89 Other myelitis
G04.9 Encephalitis, myelitis and encephalomyelitis, unspecified
G04.90 Encephalitis and encephalomyelitis, unspecified
G04.91 Myelitis, unspecified
G05 Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere
G05.3 Encephalitis and encephalomyelitis in diseases classified elsewhere
G05.4 Myelitis in diseases classified elsewhere
G06 Intracranial and intraspinal abscess and granuloma
G06.0 Intracranial abscess and granuloma
G06.1 Intraspinal abscess and granuloma
G06.2 Extradural and subdural abscess, unspecified
G07 Intracranial and intraspinal abscess and granuloma in diseases classified elsewhere
G08 Intracranial and intraspinal phlebitis and thrombophlebitis
G09 Sequelae of inflammatory diseases of central nervous system

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