G20

Non-Billable

ChapterG00–G99

Rankcategory

Official Description

Parkinson's disease

Metadata & Insights

•2026 ICD-10-CM Edition - Effective October 1, 2025.
•Non-billable category (requires more specific sub-code).
•Chapter 6: Diseases of the Nervous System (G00-G99).

CH6 Parent Instructions

Excludes2(Not included here)

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)

Instructional Notes

Includes

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

Use 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-)

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.BParkinson's disease with dyskinesia

G20.CParkinsonism, unspecified

Applicable Ancestor Context

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

chapterCH6

Diseases of the nervous system (G00-G99)

View context instructions

Alphabetic Index Mentions

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

23 raw paths

Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety)7 unique routes

in (due to)(3 variants)

paralysis agitans→G20(2 variants)

with behavioral disturbance→G20

Parkinson's disease→G20

with(4 variants)

Parkinson's disease→G20(2 variants)

with behavioral disturbance→G20

Parkinsonism→G20(2 variants)

with behavioral disturbance→G20

Disease, diseased9 unique routes