G21Secondary parkinsonism
Code usage status
Primary diagnosis
Select a more specific code
Apply only when it matches the confirmed diagnosis and the documented clinical record.
Specificity
Do not use G21 directly
Use the most specific code supported by the record.
- Chapter VI
- Diseases of the nervous system
- Group G20-G26
- Extrapyramidal and movement disorders
- Official Vietnamese name
- Hội chứng Parkinson thứ phát
Related G21 codes
G21.0
Primary diagnosis candidate
Malignant neuroleptic syndrome
G21.1
Primary diagnosis candidate
Other drug-induced secondary parkinsonism
G21.2
Primary diagnosis candidate
Secondary parkinsonism due to other external agents
G21.3
Primary diagnosis candidate
Postencephalitic parkinsonism
G21.4
Primary diagnosis candidate
Vascular parkinsonism
G21.8
Primary diagnosis candidate
Other secondary parkinsonism
G21.9
Primary diagnosis candidate
Secondary parkinsonism, unspecified
Clinical record checklist
View coding guide →- Confirm that the code matches the final documented diagnosis.
- Use one primary-diagnosis code and record only relevant additional conditions.
- Review Ministry indicators, inclusions, exclusions and notes.
- Do not infer a diagnosis beyond the clinical record.
2026 regulatory basis
Indicators are taken from columns 24–29 of the classification accompanying Circular 06/2026/TT-BYT, cross-referenced with Decision 1849/QĐ-BYT and Official Dispatch 4059/BYT-BH.
