J21Acute bronchiolitis
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 J21 directly
Use the most specific code supported by the record.
- Chapter X
- Diseases of the respiratory system
- Group J20-J22
- Other acute lower respiratory infections
- Official Vietnamese name
- Viêm tiểu phế quản cấp tính
- Additional WHO coding guidance
- Incl.: with bronchospasm
Related J21 codes
J21.0
Primary diagnosis candidate
Acute bronchiolitis due to respiratory syncytial virus
J21.1
Primary diagnosis candidate
Acute bronchiolitis due to human metapneumovirus
J21.8
Primary diagnosis candidate
Acute bronchiolitis due to other specified organisms
J21.9
Primary diagnosis candidate
Acute bronchiolitis, 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.
