2026 ICD-10-CM Diagnosis Code G20Parkinson's disease

ICD-10-CM Codes›G00–G99›G20-G26›G20

ICD-10-CM G20
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G20 is a non-billable ICD-10-CM category code for Parkinson's disease, so it cannot be submitted on claims. Use a more specific code from this category instead, such as G20.A1, G20.A2, G20.B1, and G20.B2. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parkinson`s disease.

Code Identity

ICD-10-CM Code
G20
Billable Status
No — Non-Billable Category
Code Describes
Parkinson's disease
Short Description
Parkinson's disease
Same as the full description in the CMS dataset.
Chapter
G20-G26
Extrapyramidal and movement disorders

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG20-G26Extrapyramidal and movement disorders
CategoryG20Parkinson's disease
This CodeG20Parkinson's disease

Specific Coding for Parkinson's diseaseOverview

Non-specific codes like G20 require more characters. Use one of these billable codes instead:

  • G20.A for Parkinson's disease without dyskinesia

  • Use G20.A1 for Parkinson's disease without dyskinesia, without mention of fluctuations

  • Use G20.A2 for Parkinson's disease without dyskinesia, with fluctuations

  • G20.B for Parkinson's disease with dyskinesia

  • Use G20.B1 for Parkinson's disease with dyskinesia, without mention of fluctuations

  • Use G20.B2 for Parkinson's disease with dyskinesia, with fluctuations

  • Use G20.C for Parkinsonism, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Hemiparkinsonism
  • Idiopathic Parkinsonism or Parkinson's disease
  • Paralysis agitans
  • Primary Parkinsonism or Parkinson's disease

Use Additional Code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS004
Parkinson`s disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Parkinson's Disease

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.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G20 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
332.0 Paralysis agitans
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2023No changes
FY 2024RevisedCode revised
FY 2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G20Overview

Is G20 (Parkinson's disease) a billable code?

No. This is a category header that groups the codes for Parkinson's disease, and headers cannot be submitted on claims. Claims for Parkinson's disease need a more specific code from this category, such as G20.A1, G20.A2, and G20.B1.

What is the ICD-9 equivalent of G20?

Under the General Equivalence Mappings, Parkinson's disease converts to ICD-9-CM 332.0 (paralysis agitans). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.