ICD-10 Code for Parkinsonism
Also indexed as (idiopathic) (primary)
The ICD-10-CM code for parkinsonism is G20.C — Parkinsonism, unspecified. This is the code the Alphabetic Index gives for parkinsonism with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
G20.C is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which parkinsonism code should you use?
The Alphabetic Index lists 12 codes under Parkinsonism. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| with neurogenic orthostatic hypotension | G90.3 | Multi-system degeneration of the autonomic nervous system | |
| arteriosclerotic | G21.4 | Vascular parkinsonism | |
| dementia | G20.C | Parkinsonism, unspecified | |
| medication-induced NEC | G21.19 | Other drug induced secondary parkinsonism | |
| neuroleptic induced | G21.11 | Neuroleptic induced parkinsonism | |
| postencephalitic | G21.3 | Postencephalitic parkinsonism | |
| secondary | G21.9 | Secondary parkinsonism, unspecified | |
| syphilitic | A52.19 | Other symptomatic neurosyphilis | |
| treatment-induced NEC | G21.19 | Other drug induced secondary parkinsonism | |
| vascular | G21.4 | Vascular parkinsonism |
Parkinsonism dementia
| with behavioral disturbance | G20.C | Parkinsonism, unspecified |
Parkinsonism due to
Parkinsonism secondary
| specified NEC | G21.8 | Other secondary parkinsonism | |
| due to › arteriosclerosis | G21.4 | Vascular parkinsonism | |
| due to › drugs NEC | G21.19 | Other drug induced secondary parkinsonism | |
| due to › encephalitis | G21.3 | Postencephalitic parkinsonism | |
| due to › external agents NEC | G21.2 | Secondary parkinsonism due to other external agents | |
| due to › syphilis | A52.19 | Other symptomatic neurosyphilis | |
| due to › drugs NEC › neuroleptic | G21.11 | Neuroleptic induced parkinsonism |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources