G20.A vs G20.C
G20.A (Parkinson's disease without dyskinesia) compared with G20.C (Parkinsonism, unspecified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. G20.C carries an Excludes1 note covering G20.A: “Parkinson's disease without dyskinesia (G20.A-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| G20.AParkinson's disease without dyskinesia | G20.CParkinsonism, unspecified | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | G00-G99 — Diseases of the Nervous System (G00-G99) | G00-G99 — Diseases of the Nervous System (G00-G99) |
| Definition | Parkinson's disease without dyskinesia is a non-billable ICD-10-CM category code (G20.A). | Parkinsonism, unspecified is a billable ICD-10-CM diagnosis code (G20.C). |
| Includes | — | Parkinsonism, NOS |
| 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-) | 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-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources