ICD-10-CM Code G20

Parkinson's disease

Version 2021 Billable Code

Valid for Submission

G20 is a billable code used to specify a medical diagnosis of parkinson's disease. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code G20 might also be used to specify conditions or terms like adult-onset dystonia parkinsonism, atypical juvenile parkinsonism, atypical parkinsonism, autosomal dominant late onset parkinson disease, cerebral degeneration due to parkinson's disease, dementia associated with parkinson's disease, etc

Short Description:Parkinson's disease
Long Description:Parkinson's disease

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code G20:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Hemiparkinsonism
  • Idiopathic Parkinsonism or Parkinson's disease
  • Paralysis agitans
  • Parkinsonism or Parkinson's disease NOS
  • Primary Parkinsonism or Parkinson's disease

Use Additional Code

Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
  • code to identify:
  • dementia with behavioral disturbance F02.81
  • dementia without behavioral disturbance F02.80

Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • dementia with Parkinsonism G31.83

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code G20 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Adult-onset dystonia parkinsonism
  • Atypical juvenile parkinsonism
  • Atypical Parkinsonism
  • Autosomal dominant late onset Parkinson disease
  • Cerebral degeneration due to Parkinson's disease
  • Dementia associated with Parkinson's Disease
  • Dementia due to Parkinson's disease
  • Dissociative neurological symptom disorder co-occurrent with Parkinsonism
  • Dopamine transporter deficiency syndrome
  • Early onset parkinsonism and intellectual disability syndrome
  • Frontotemporal dementia with parkinsonism-17
  • Functional parkinsonism
  • Hemiparkinsonism hemiatrophy syndrome
  • Hypokinetic parkinsonian dysphonia
  • Juvenile paralysis agitans of Hunt
  • Juvenile Parkinson's disease
  • O/E - Parkinsonian tremor
  • Pallidal degeneration
  • Parkinsonian facies
  • Parkinsonian pyramidal syndrome
  • Parkinsonian tremor
  • Parkinsonism
  • Parkinsonism due to heredodegenerative disorder
  • Parkinson's disease
  • Parkinson's facies
  • Perry syndrome
  • Psychosis co-occurrent and due to Parkinson's disease
  • Rapid onset dystonia parkinsonism
  • Restrictive lung disease
  • Restrictive lung disease due to Parkinson disease
  • Sporadic Parkinson disease
  • Symptomatic parkinsonism
  • X-linked dystonia parkinsonism
  • X-linked parkinsonism with spasticity syndrome
  • Young onset Parkinson disease

Clinical Information

  • PARKINSON DISEASE-. 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

Convert G20 to ICD-9

  • 332.0 - Paralysis agitans (Approximate Flag)

Code Classification

  • Diseases of the nervous system (G00–G99)
    • Extrapyramidal and movement disorders (G20-G26)
      • Parkinson's disease (G20)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Parkinson's Disease

Also called: Paralysis agitans, Shaking palsy

Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.

Symptoms begin gradually, often on one side of the body. Later they affect both sides. They 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.

There is no lab test for PD, so it can be difficult to diagnose. Doctors use a medical history and a neurological examination to diagnose it.

PD usually begins around age 60, but it can start earlier. It is more common in men than in women. There is no cure for PD. A variety of medicines sometimes help symptoms dramatically. Surgery and deep brain stimulation (DBS) can help severe cases. With DBS, electrodes are surgically implanted in the brain. They send electrical pulses to stimulate the parts of the brain that control movement.

NIH: National Institute of Neurological Disorders and Stroke

  • Deep brain stimulation (Medical Encyclopedia)
  • Parkinson disease (Medical Encyclopedia)
  • Secondary parkinsonism (Medical Encyclopedia)
  • Swallowing problems (Medical Encyclopedia)

[Learn More]

Parkinson disease Parkinson disease is a progressive disorder of the nervous system. The disorder affects several regions of the brain, especially an area called the substantia nigra that controls balance and movement.Often the first symptom of Parkinson disease is trembling or shaking (tremor) of a limb, especially when the body is at rest. Typically, the tremor begins on one side of the body, usually in one hand. Tremors can also affect the arms, legs, feet, and face. Other characteristic symptoms of Parkinson disease include rigidity or stiffness of the limbs and torso, slow movement (bradykinesia) or an inability to move (akinesia), and impaired balance and coordination (postural instability). These symptoms worsen slowly over time.Parkinson disease can also affect emotions and thinking ability (cognition). Some affected individuals develop psychiatric conditions such as depression and visual hallucinations. People with Parkinson disease also have an increased risk of developing dementia, which is a decline in intellectual functions including judgment and memory.Generally, Parkinson disease that begins after age 50 is called late-onset disease. The condition is described as early-onset disease if signs and symptoms begin before age 50. Early-onset cases that begin before age 20 are sometimes referred to as juvenile-onset Parkinson disease.
[Learn More]