2023 ICD-10-CM Diagnosis Code G20

Parkinson's disease

    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  • G20 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 G20 became effective on October 1, 2022.
  • This is the American ICD-10-CM version of G20 - other international versions of ICD-10 G20 may differ.
Applicable To
  • Hemiparkinsonism
  • Idiopathic Parkinsonism or Parkinson's disease
  • Paralysis agitans
  • Parkinsonism or Parkinson's disease NOS
  • Primary Parkinsonism or Parkinson's disease
Use Additional
Use Additional Help
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.
  • code, if applicable, to identify:
  • dementia with anxiety (
    ICD-10-CM Diagnosis Code F02.84

    Dementia in other diseases classified elsewhere, unspecified severity, with anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Major neurocognitive disorder in other diseases classified elsewhere unspecified severity, with anxiety
    F02.84
    ,
    ICD-10-CM Diagnosis Code F02.A4

    Dementia in other diseases classified elsewhere, mild, with anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Major neurocognitive disorder in other diseases classified elsewhere, mild, with anxiety
    F02.A4
    ,
    ICD-10-CM Diagnosis Code F02.B4

    Dementia in other diseases classified elsewhere, moderate, with anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Major neurocognitive disorder in other diseases classified elsewhere, moderate, with anxiety
    F02.B4
    ,
    ICD-10-CM Diagnosis Code F02.C4

    Dementia in other diseases classified elsewhere, severe, with anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Major neurocognitive disorder in other diseases classified elsewhere, severe, with anxiety
    F02.C4
    )
  • dementia with behavioral disturbance (
    ICD-10-CM Diagnosis Code F02.81

    Dementia in other diseases classified elsewhere, unspecified severity, with behavioral disturbance

      2016 2017 2018 2019 2020 2021 2022 2023 - Converted to Parent Code Non-Billable/Non-Specific Code
    F02.81-
    ,
    ICD-10-CM Diagnosis Code F02.A1

    Dementia in other diseases classified elsewhere, mild, with behavioral disturbance

      2023 - New Code Non-Billable/Non-Specific Code
    F02.A1-
    ,
    ICD-10-CM Diagnosis Code F02.B1

    Dementia in other diseases classified elsewhere, moderate, with behavioral disturbance

      2023 - New Code Non-Billable/Non-Specific Code
    F02.B1-
    ,
    ICD-10-CM Diagnosis Code F02.C1

    Dementia in other diseases classified elsewhere, severe, with behavioral disturbance

      2023 - New Code Non-Billable/Non-Specific Code
    F02.C1-
    )
  • dementia with mood disturbance (
    ICD-10-CM Diagnosis Code F02.83

    Dementia in other diseases classified elsewhere, unspecified severity, with mood disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, unspecified severity, with mood disturbance such as depression, apathy, or anhedonia
    • Major neurocognitive disorder in other diseases classified elsewhere unspecified severity, with mood disturbance such as with depression, apathy, or anhedonia
    F02.83
    ,
    ICD-10-CM Diagnosis Code F02.A3

    Dementia in other diseases classified elsewhere, mild, with mood disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, mild, with mood disturbance such as depression, apathy, or anhedonia
    • Major neurocognitive disorder in other diseases classified elsewhere, mild, with mood disturbance such as depression, apathy, or anhedonia
    F02.A3
    ,
    ICD-10-CM Diagnosis Code F02.B3

    Dementia in other diseases classified elsewhere, moderate, with mood disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, moderate, with mood disturbance such as depression, apathy, or anhedonia
    • Major neurocognitive disorder in other diseases classified elsewhere, moderate, with mood disturbance such as depression, apathy, or anhedonia
    F02.B3
    ,
    ICD-10-CM Diagnosis Code F02.C3

    Dementia in other diseases classified elsewhere, severe, with mood disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, severe, with mood disturbance such as depression, apathy, or anhedonia
    • Major neurocognitive disorder in other diseases classified elsewhere, severe, with mood disturbance such as depression, apathy, or anhedonia
    F02.C3
    )
  • dementia with psychotic disturbance (
    ICD-10-CM Diagnosis Code F02.82

    Dementia in other diseases classified elsewhere, unspecified severity, with psychotic disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, unspecified severity, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    • Major neurocognitive disorder in other diseases classified elsewhere, unspecified, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    F02.82
    ,
    ICD-10-CM Diagnosis Code F02.A2

    Dementia in other diseases classified elsewhere, mild, with psychotic disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, mild, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    • Major neurocognitive disorder in other diseases classified elsewhere, mild, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    F02.A2
    ,
    ICD-10-CM Diagnosis Code F02.B2

    Dementia in other diseases classified elsewhere, moderate, with psychotic disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, moderate, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    • Major neurocognitive disorder in other diseases classified elsewhere, moderate, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    F02.B2
    ,
    ICD-10-CM Diagnosis Code F02.C2

    Dementia in other diseases classified elsewhere, severe, with psychotic disturbance

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, severe, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    • Major neurocognitive disorder in other diseases classified elsewhere, severe, with psychotic disturbance such as hallucinations, paranoia, suspiciousness, or delusional state
    F02.C2
    )
  • dementia without behavioral disturbance (
    ICD-10-CM Diagnosis Code F02.80

    Dementia in other diseases classified elsewhere, unspecified severity, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety

      2016 2017 2018 2019 2020 2021 2022 2023 - Revised Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere NOS
    • Major neurocognitive disorder in other diseases classified elsewhere NOS
    F02.80
    ,
    ICD-10-CM Diagnosis Code F02.A0

    Dementia in other diseases classified elsewhere, mild, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, mild, NOS
    • Major neurocognitive disorder in other diseases classified elsewhere, mild, NOS
    F02.A0
    ,
    ICD-10-CM Diagnosis Code F02.B0

    Dementia in other diseases classified elsewhere, moderate, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, moderate, NOS
    • Major neurocognitive disorder in other diseases classified elsewhere, moderate, NOS
    F02.B0
    ,
    ICD-10-CM Diagnosis Code F02.C0

    Dementia in other diseases classified elsewhere, severe, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety

      2023 - New Code Billable/Specific Code Manifestation Code
    Applicable To
    • Dementia in other diseases classified elsewhere, severe, NOS
    • Major neurocognitive disorder in other diseases classified elsewhere, severe, NOS
    F02.C0
    )
  • mild neurocognitive disorder due to known physiological condition (
    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
    F06.7-
    )
The following code(s) above G20 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 G20:
  • 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
Approximate Synonyms
  • Dementia associated with parkinson's disease
  • Dementia in parkinsons disease
  • Parkinsonism
  • Parkinsons disease
  • Restrictive lung disease due to parkinsons disease
  • Restrictive lung mechanics due to parkinsons disease
Clinical Information
  • A disease characterized as a progressive motor disability manifested by tremors, shaking, muscular rigidity, and lack of postural reflexes.
  • A progressive degenerative disorder of the central nervous system characterized by loss of dopamine producing neurons in the substantia nigra and the presence of lewy bodies in the substantia nigra and locus coeruleus. Signs and symptoms include tremor which is most pronounced during rest, muscle rigidity, slowing of the voluntary movements, a tendency to fall back, and a mask-like facial expression.
  • A progressive disorder of the nervous system marked by muscle tremors, muscle rigidity, decreased mobility, stooped posture, slow voluntary movements, and a mask-like facial expression.
  • A progressive, degenerative neurologic disease characterized by a tremor that is maximal at rest, retropulsion (i.e. A tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. Lewy bodies are present in the substantia nigra and locus coeruleus but may also be found in a related condition (lewy body disease, diffuse) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)
  • Parkinson's disease is a disorder that affects nerve cells, or neurons, in a part of the brain that controls muscle movement. In parkinson's, neurons that make a chemical called dopamine die or do not work properly. Dopamine normally sends signals that help coordinate your movements. No one knows what damages these cells. Symptoms of parkinson's disease may include
    • trembling of hands, arms, legs, jaw and face
    • stiffness of the arms, legs and trunk
    • slowness of movement
    • poor balance and coordination
    as symptoms get worse, people with the disease may have trouble walking, talking or doing simple tasks. They may also have problems such as depression, sleep problems or trouble chewing, swallowing or speaking. Parkinson's usually begins around age 60, but it can start earlier. It is more common in men than in women. There is no cure for parkinson's disease. A variety of medicines sometimes help symptoms dramatically.
  • Progressive, degenerative disorder of the nervous system characterized by tremors, rigidity, bradykinesia, postural instability, and gait abnormalities; caused by a loss of neurons and a decrease of dopamine in the basal ganglia.
ICD-10-CM G20 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 G20 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 G20:
  • Code First: R47.82
    , F06.7
    , F02
    ICD-10-CM Diagnosis Code R47.82

    Fluency disorder in conditions classified elsewhere

      2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code Manifestation Code
    Applicable To
    • Stuttering in conditions classified elsewhere
    Code First
    • underlying disease or condition, such as:
    • Parkinson's disease (G20)
    Type 1 Excludes
    • adult onset fluency disorder (F98.5)
    • childhood onset fluency disorder (F80.81)
    • fluency disorder (stuttering) following cerebrovascular disease (I69. with final characters -23)
    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
    ICD-10-CM Diagnosis Code F02

    Dementia in other diseases classified elsewhere

      2016 2017 2018 2019 2020 2021 2022 2023 Non-Billable/Non-Specific Code
    Code First
    • the underlying physiological condition, such as:
    • Alzheimer's (G30.-)
    • cerebral lipidosis (E75.4)
    • Creutzfeldt-Jakob disease (A81.0-)
    • dementia with Lewy bodies (G31.83)
    • dementia with Parkinsonism (G31.83)
    • epilepsy and recurrent seizures (G40.-)
    • frontotemporal dementia (G31.09)
    • hepatolenticular degeneration (E83.0)
    • human immunodeficiency virus [HIV] disease (B20)
    • Huntington's disease (G10)
    • hypercalcemia (E83.52)
    • hypothyroidism, acquired (E00-E03.-)
    • intoxications (T36-T65)
    • Jakob-Creutzfeldt disease (A81.0-)
    • multiple sclerosis (G35)
    • neurosyphilis (A52.17)
    • niacin deficiency [pellagra] (E52)
    • Parkinson's disease (G20)
    • Pick's disease (G31.01)
    • polyarteritis nodosa (M30.0)
    • prion disease (A81.9)
    • systemic lupus erythematosus (M32.-)
    • traumatic brain injury (S06.-)
    • trypanosomiasis (B56.-, B57.-)
    • vitamin B deficiency (E53.8)
    Includes
    • Major neurocognitive disorder in other diseases classified elsewhere
    Type 1 Excludes
    • mild neurocognitive disorder due to known physiological condition with or without behavioral disturbance (F06.7-)
    Type 2 Excludes

Diagnosis Index entries containing back-references to G20:

ICD-10-CM Codes Adjacent To G20
G12.25 Progressive spinal muscle atrophy
G12.29 Other motor neuron disease
G12.8 Other spinal muscular atrophies and related syndromes
G12.9 Spinal muscular atrophy, unspecified
G13 Systemic atrophies primarily affecting central nervous system in diseases classified elsewhere
G13.0 Paraneoplastic neuromyopathy and neuropathy
G13.1 Other systemic atrophy primarily affecting central nervous system in neoplastic disease
G13.2 Systemic atrophy primarily affecting the central nervous system in myxedema
G13.8 Systemic atrophy primarily affecting central nervous system in other diseases classified elsewhere
G14 Postpolio syndrome
G20 Parkinson's disease
G21 Secondary parkinsonism
G21.0 Malignant neuroleptic syndrome
G21.1 Other drug-induced secondary parkinsonism
G21.11 Neuroleptic induced parkinsonism
G21.19 Other drug induced secondary parkinsonism
G21.2 Secondary parkinsonism due to other external agents
G21.3 Postencephalitic parkinsonism
G21.4 Vascular parkinsonism
G21.8 Other secondary parkinsonism
G21.9 Secondary parkinsonism, unspecified

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