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ICD-10-CM 2027

ICD-10 code for Hemiparkinsonism

G20.C

Parkinsonism, unspecified

✓ Billable / specific

From the official ICD-10-CM alphabetic index entry “Hemiparkinsonism”. Page updated September 29, 2026.

About coding Hemiparkinsonism

The ICD-10-CM code for Hemiparkinsonism is G20.C (Parkinsonism, unspecified).

Within G20, choose G20.C (Parkinsonism, unspecified) only when documentation doesn't support a more specific option: without dyskinesia (G20.A) and with dyskinesia (G20.B).

Don't report G20.C together with the conditions in its Excludes1 note: Parkinson's disease NOS (G20.A1), Parkinson's disease with dyskinesia (G20.B-), Parkinson's disease without dyskinesia (G20.A-) and secondary parkinsonism (G21.-).

Use an additional 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) and 1 more.

Don't confuse with (Excludes1 for G20.C)

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

Common questions about Hemiparkinsonism ICD-10 codes

What is the ICD-10 code for Hemiparkinsonism?

G20.C — Parkinsonism, unspecified.

Is G20.C billable?

Yes. G20.C is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can G20.C be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict G20.C as a principal diagnosis.

Is G20.C a CC or MCC?

No. G20.C is neither a CC nor an MCC under MS-DRG v44.0.