ICD-10-CM · Chapter 6 · G00-G99
G21 Secondary parkinsonism
Excludes 1 (cannot be coded together)
- Huntington's disease (G10)
- neurocognitive disorder with Lewy bodies (G31.83)
- Shy-Drager syndrome (G90.3)
- syphilitic Parkinsonism (A52.19)
Subcodes
Each subcode links to a detail page with full clinical annotations.
| Code | Description | Billable |
|---|---|---|
| G21..0 | Malignant neuroleptic syndrome | Yes |
| G21..1 | Other drug-induced secondary parkinsonism | No |
| G21..11 | Neuroleptic induced parkinsonism | Yes |
| G21..19 | Other drug induced secondary parkinsonism | Yes |
| G21..2 | Secondary parkinsonism due to other external agents | Yes |
| G21..3 | Postencephalitic parkinsonism | Yes |
| G21..4 | Vascular parkinsonism | Yes |
| G21..8 | Other secondary parkinsonism | Yes |
| G21..9 | Secondary parkinsonism, unspecified | Yes |
Last reviewed: September 2026