What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).
When is it used?
- May be used when a clinician documents parkinson's disease in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
6Diseases of the nervous system (G00-G99)
block
G20-G26Extrapyramidal and movement disorders
currentG20-G26
Official coding notes
Inclusion terms
- Hemiparkinsonism
- Idiopathic Parkinsonism or Parkinson's disease
- Paralysis agitans
- Primary Parkinsonism or Parkinson's disease
Applicable to
- 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-)
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-)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
NeurologistGeneral Physician
Related codes
Sibling codes
Mapped diagnoses and classifications
SNOMED_CT 722964001high
Atypical Parkinsonism
Source: SNOMED International ICD-10 map
SNOMED_CT 725146001high
Atypical juvenile parkinsonism
Source: SNOMED International ICD-10 map
SNOMED_CT 1259080009high
Autonomic disorder due to Parkinson disease
Source: SNOMED International ICD-10 map
SNOMED_CT 716662004high
Autosomal dominant late onset Parkinson disease
Source: SNOMED International ICD-10 map
SNOMED_CT 1156822001high
Autosomal recessive familial Parkinson disease
Source: SNOMED International ICD-10 map
SNOMED_CT 438513002high
Cerebral degeneration due to Parkinson's disease
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
G20
Replacement codes
G20.C — Parkinsonism, unspecified
Common synonyms
Parkinson's disease
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.