J21
Acute bronchiolitis
Non-billable headerNot valid on its own. Use one of the more specific codes under it.
J21 is a non-billable ICD-10-CM code category for acute bronchiolitis. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are J21.0 Acute bronchiolitis due to respiratory syncytial virus; J21.1 Acute bronchiolitis due to human metapneumovirus; J21.8 Acute bronchiolitis due to other specified organisms and J21.9 Acute bronchiolitis, unspecified. Its coding notes include a Use additional code instruction and 11 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
Also from chapter/block level (7 notes)
Inherited from Chapter 10 Diseases of the respiratory system
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
This code
- respiratory bronchiolitis interstitial lung disease (J84.115)
Also from chapter/block level (10 notes)
Inherited from J20–J22 Other acute lower respiratory infections
- chronic obstructive pulmonary disease with acute lower respiratory infection (J44.0)
Inherited from Chapter 10 Diseases of the respiratory system
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- smoke inhalation (T59.81-)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Includes
Further defines or gives examples of the content of the category.
This code
- acute bronchiolitis with bronchospasm
Notes
Also from chapter/block level (1 note)
Inherited from Chapter 10 Diseases of the respiratory system
- When a respiratory condition is described as occurring in more than one site and is not specifically indexed, it should be classified to the lower anatomic site (e.g. tracheobronchitis to bronchitis in J40).