Is ICD-10-CM code G20 billable?

No, G20 (Parkinson's disease) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code G20 belong to?

G20 belongs to Chapter 6 of the ICD-10-CM tabular list: G00–G99 (Diseases of the Nervous System).

G20Not billable, use a more specific code below

Parkinson's disease

In Extrapyramidal and movement disorders (G20-G26), chapter 6: Diseases of the Nervous System

5 billable codes under G20: none are a CC or MCC; all map to HCC 199 (Parkinson and Other Degenerative Disease of Basal Ganglia).An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Includes: conditions that are coded here

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

Use additional code: add a second code for this, listed after this one

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-)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers default dominant or nondominant side for hemiplegia and monoplegia, and use and sequencing of G89 pain codes, including postoperative, chronic, and neoplasm-related pain.

Dominant/nondominant side (page 45)
Pain - Category G89 (page 45)

Read Section I.C.6 (page 45)

All codes under G20

G20 can't be used on a claim. Pick a billable code below; grey headings group them.

G20 MS-DRGs

As the principal diagnosis, all 5 billable codes under G20 group to MS-DRG 056 or 057 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Other codes that refer to G20

Notes on these codes point to G20.

F02 Code First: Parkinson's disease (G20.-)
F06.7 Code First: Parkinson's disease (G20.-)
F98.4 Excludes2: movement disorders of organic origin (G20-G25)
R25 Excludes1: specific movement disorders (G20-G26)
R47.82 Code First: Parkinson's disease (G20.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015.

FY2024: Subcodes were added, so G20 is no longer billable on its own. New codes for cases coded here before: G20.A1 (Parkinson's disease without dyskinesia, without mention of fluctuations), G20.A2 (Parkinson's disease without dyskinesia, with fluctuations), G20.B1 (Parkinson's disease with dyskinesia, without mention of fluctuations), G20.B2 (Parkinson's disease with dyskinesia, with fluctuations), G20.C (Parkinsonism, unspecified).

ICD-9-CM equivalent

Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).

332.0 Paralysis agitans (approximate)

ICD-9 to ICD-10 converter