Parkinson's disease (G20) ICD-10-CM
The G20 code range covers parkinson's disease with 8 ICD-10-CM diagnosis codes. 5 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
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
- Primary Parkinsonism or Parkinson's disease
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, if applicable, to identify:
- dementia with anxiety F02.84 F02.A4 F02.B4 F02.C4
- dementia with behavioral disturbance F02.81 F02.A1 F02.B1 F02.C1
- dementia with mood disturbance F02.83 F02.A3 F02.B3 F02.C3
- dementia with psychotic disturbance F02.82 F02.A2 F02.B2 F02.C2
- dementia without behavioral disturbance F02.80 F02.A0 F02.B0 F02.C0
- mild neurocognitive disorder due to known physiological condition F06.7
Codes in the G20 Range 8 codes · 5 billable
- G20 Parkinson's diseaseNon-billable
- G20.A Parkinson's disease without dyskinesiaNon-billable
- G20.A1 Parkinson's disease without dyskinesia, without mention of fluctuations
- G20.A2 Parkinson's disease without dyskinesia, with fluctuations
- G20.B Parkinson's disease with dyskinesiaNon-billable
- G20.B1 Parkinson's disease with dyskinesia, without mention of fluctuations
- G20.B2 Parkinson's disease with dyskinesia, with fluctuations
- G20.C Parkinsonism, unspecified
About the G20 Code Range
The ICD-10 code for Parkinson's disease is primarily G20, with detailed subcodes distinguishing cases with or without dyskinesia and fluctuations. These codes facilitate precise classification of Parkinson's disease and related parkinsonian disorders in medical records and billing.
The main code G20 covers Parkinson's disease in general, while subcategories such as G20.A1 represent Parkinson's disease without dyskinesia and fluctuations, including variations like juvenile or young-onset Parkinson's and conditions like dementia due to Parkinson's disease. G20.A2 identifies Parkinson's disease without dyskinesia but with motor fluctuations, often described as "off-periods" not responsive to oral treatments. Codes G20.B1 and G20.B2 cover Parkinson's disease with dyskinesia, differentiated by the presence or absence of fluctuations. Additionally, G20.C captures unspecified parkinsonism, encompassing a broad range of related syndromes such as Parkinsonian tremor and atypical parkinsonism. This structured coding helps healthcare providers document various Parkinson's presentations accurately and supports effective patient management and analytics.
Questions About This Page
How many billable codes are in the G20 range?
Of the 8 codes in this range, 5 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the G20 range classify?
The range classifies parkinson's disease. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
