Is G20.C a billable ICD-10-CM code?

Yes. G20.C is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does G20.C sit in the tabular list?

Diseases of the nervous system (G00-G99), in the block Extrapyramidal and movement disorders (G20-G26).

What cannot be coded together with G20.C?

G20.C carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

G20.C

G20.C — Parkinsonism, unspecified

Billable / specific codeICD-10-CM

G20.C is a billable, specific ICD-10-CM code for parkinsonism, unspecified. It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

Parkinson's disease NOS (G20.A1)
Parkinson's disease with dyskinesia (G20.B-)
Parkinson's disease without dyskinesia (G20.A-)
secondary parkinsonism (G21.-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Parkinsonism, NOS

Risk adjustment

G20.C risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

HCC 199 Parkinson and Other Degenerative Disease of Basal Ganglia0.615 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

G20.C is named in 14 Medicare coverage policies — 14 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A53064Billing and Coding: Outpatient Occupational Therapy
A53065Billing and Coding: Outpatient Physical Therapy
A56612Billing and Coding: CT of the Head
A56874Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT)

How G20.C is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G20.C.

Hemiparkinsonism
Parkinsonism(idiopathic) (primary)
Pyramidopallidonigral syndrome
Paralysis, paralytic›agitans
Parkinsonism›dementia
Syndrome›pyramidopallidonigral
Dementia›in›paralysis agitans
Dementia›with›Parkinsonism
Parkinsonism›dementia›with behavioral disturbance
Dementia›in›paralysis agitans›with behavioral disturbance
Dementia›with›Parkinsonism›with behavioral disturbance

Related codes at this level

Codes that share G20. If G20.C is not quite right, the correct code is usually one of these.

Questions about G20.C

Is G20.C a billable ICD-10-CM code?: Yes. G20.C is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G20.C sit in the tabular list?: Diseases of the nervous system (G00-G99), in the block Extrapyramidal and movement disorders (G20-G26).
What cannot be coded together with G20.C?: G20.C carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.