2023 ICD-10-CM Diagnosis Code G31.9

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Degenerative disease of nervous system, unspecified

    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  • G31.9 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 G31.9 became effective on October 1, 2022.
  • This is the American ICD-10-CM version of G31.9 - other international versions of ICD-10 G31.9 may differ.
The following code(s) above G31.9 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 G31.9:
  • 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
  • G31
    ICD-10-CM Diagnosis Code G31

    Other degenerative diseases of nervous system, not elsewhere classified

      2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
    Type 2 Excludes
    Use Additional
    Other degenerative diseases of nervous system, not elsewhere classified
Approximate Synonyms
  • Acquired cerebral atrophy
  • Cerebellar paraneoplastic degeneration
  • Cerebral atrophy, acquired
  • Cerebral degeneration in childhood
  • Degenerative brain disorder
  • Paraneoplastic cerebellar degeneration
Clinical Information
  • A disorder of the central nervous system characterized by gradual and progressive loss of neural tissue and neurologic function.
  • Hereditary and sporadic conditions which are characterized by progressive nervous system dysfunction. These disorders are often associated with atrophy of the affected central or peripheral nervous system structures.
  • Neurologic disorders characterized by progressive nervous system dysfunction and loss of neural tissue.
ICD-10-CM G31.9 is grouped within Diagnostic Related Group(s) (MS-DRG v40.0):
  • 056 Degenerative nervous system disorders with mcc
  • 057 Degenerative nervous system disorders without mcc

Convert G31.9 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
Code annotations containing back-references to G31.9:
  • Type 1 Excludes: G31.84
    , F06.7
    ICD-10-CM Diagnosis Code G31.84

    Mild cognitive impairment of uncertain or unknown etiology

      2016 2017 2018 2019 2020 2021 2022 2023 - Revised Code Billable/Specific Code
    Applicable To
    • Mild cognitive disorder NOS
    • Mild neurocognitive disorder of uncertain or unknown etiology
    Type 1 Excludes
    • age related cognitive decline (R41.81)
    • altered mental status (R41.82)
    • cerebral degeneration (G31.9)
    • cerebrovascular diseases (I60-I69)
    • change in mental status (R41.82)
    • cognitive deficits following (sequelae of) cerebral hemorrhage or infarction (I69.01-, I69.11-, I69.21-, I69.31-, I69.81-, I69.91-)
    • cognitive impairment due to intracranial or head injury (S06.-)
    • dementia (F01.-, F02.-, F03)
    • mild neurocognitive disorder due to a known physiological condition (F06.7-)
    • neurologic neglect syndrome (R41.4)
    • personality change, nonpsychotic (F68.8)
    Use Additional
    • code to identify presence of:
    • alcohol abuse and dependence (F10.-)
    • exposure to environmental tobacco smoke (Z77.22)
    • history of tobacco dependence (Z87.891)
    • hypertension (I10-I16)
    • occupational exposure to environmental tobacco smoke (Z57.31)
    • tobacco dependence (F17.-)
    • tobacco use (Z72.0)
    ICD-10-CM Diagnosis Code F06.7

    Mild neurocognitive disorder due to known physiological condition

      2023 - New Code Non-Billable/Non-Specific Code
    Applicable To
    • Mild neurocognitive impairment due to a known physiological condition
    Code First
    • the underlying physiological condition, such as:
    • Alzheimer's disease (G30.-)
    • frontotemporal neurocognitive disorder (G31.09)
    • human immunodeficiency virus [HIV] disease (B20)
    • Huntington's disease (G10)
    • Neurocognitive disorder with Lewy bodies (G31.83)
    • Parkinson's disease (G20)
    • systemic lupus erythematosus (M32.-)
    • traumatic brain injury (S06.-)
    • vitamin B deficiency (E53-)
    Type 1 Excludes
  • Use Additional: G31
    ICD-10-CM Diagnosis Code G31

    Other degenerative diseases of nervous system, not elsewhere classified

      2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
    Type 2 Excludes
    Use Additional

Diagnosis Index entries containing back-references to G31.9:

ICD-10-CM Codes Adjacent To G31.9
G31.09 Other frontotemporal neurocognitive disorder
G31.1 Senile degeneration of brain, not elsewhere classified
G31.2 Degeneration of nervous system due to alcohol
G31.8 Other specified degenerative diseases of nervous system
G31.81 Alpers disease
G31.82 Leigh's disease
G31.83 Neurocognitive disorder with Lewy bodies
G31.84 Mild cognitive impairment of uncertain or unknown etiology
G31.85 Corticobasal degeneration
G31.89 Other specified degenerative diseases of nervous system
G31.9 Degenerative disease of nervous system, unspecified
G32 Other degenerative disorders of nervous system in diseases classified elsewhere
G32.0 Subacute combined degeneration of spinal cord in diseases classified elsewhere
G32.8 Other specified degenerative disorders of nervous system in diseases classified elsewhere
G32.81 Cerebellar ataxia in diseases classified elsewhere
G32.89 Other specified degenerative disorders of nervous system in diseases classified elsewhere
G35 Multiple sclerosis
G36 Other acute disseminated demyelination
G36.0 Neuromyelitis optica [Devic]
G36.1 Acute and subacute hemorrhagic leukoencephalitis [Hurst]
G36.8 Other specified acute disseminated demyelination

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