10ICD Code Hub

J21

Header — not billable

Acute bronchiolitis

The ICD-10 code for acute bronchiolitis is J21.

J21 is a non-billable header code. It groups related conditions but cannot be used on its own for reimbursement — select one of the 4 more specific codes below.

Clinical notes

Excludes2 (not included here)

An Excludes2 note means the excluded condition is not part of this one, but a patient can have both at the same time — in that case both codes may be reported together.

  • respiratory bronchiolitis interstitial lung disease (J84.115)

Includes

Terms listed here further define or give examples of the conditions grouped under this code — they describe what the code covers, not a separate diagnosis.

  • acute bronchiolitis with bronchospasm

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

Child codes under J21

Related codes in this category