G20.A1

Billable

ChapterG00–G99

Ranksubcategory

Official Description

Parkinson's disease without dyskinesia, without mention of fluctuations

Metadata & Insights

•2026 ICD-10-CM Edition - Effective October 1, 2025.
•Billable/specific code (valid for reimbursement).
•Chapter 6: Diseases of the Nervous System (G00-G99).

Instructional Notes

Includes

Parkinson's disease NOS
Parkinson's disease without dyskinesia, without mention of OFF episodes

General instructions are available for the parent sections:

View CH6 Notes View G20 Notes

Clinical Hierarchy

CH6Diseases of the nervous system (G00-G99)

G20-G26Extrapyramidal and movement disorders (G20-G26)

G20Parkinson's disease

G20.AParkinson's disease without dyskinesia

G20.A1Parkinson's disease without dyskinesia, without mention of fluctuations

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to G20.A1:

categoryG20

Parkinson's disease

View context instructions

chapterCH6

Diseases of the nervous system (G00-G99)

View context instructions

Alphabetic Index Mentions

These are Diagnosis Index lookup paths that route to G20.A1. Use them as entry terms for search, then confirm final coding instructions in the Tabular List and notes above.

6 raw paths

Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety)3 unique routes

in (due to)

Parkinson's disease→G20.A1

with(2 variants)

Parkinson's disease→G20.A1(2 variants)

with behavioral disturbance→G20.A1

Disease, diseased3 unique routes

Parkinson's→G20.A1(3 variants)

without dyskinesia(2 variants)

without mention of(2 variants)

fluctuations→G20.A1

OFF episodes→G20.A1

MS-DRG Classification

2026 v43.1

This code is grouped within the following Diagnosis Related Group(s) for clinical reimbursement:

DRG 056

Degenerative Nervous System Disorders with MCC

DRG 057

Degenerative Nervous System Disorders without MCC

Cross Reference

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Find surgical and procedural codes related to Parkinson's disease without dyskinesia, without mention of fluctuations.

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