J21.9 – Acute bronchiolitis, unspecified

ICD-10-CM 2027 diagnosis code · Other acute lower respiratory infections

Billable code

ICD-10-CM code J21.9

Code: J21.9 (claims format: J219)
Description: Acute bronchiolitis, unspecified
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 10. Diseases of the respiratory system (J00-J99)
Block: J20-J22 Other acute lower respiratory infections
Parent codes: J21

Notes for J21.9

Applicable to:

Bronchiolitis (acute)

Excludes1 (not coded here):

chronic bronchiolitis (J44.89)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

J21 – Acute bronchiolitis

Includes:

acute bronchiolitis with bronchospasm

Excludes2 (not included here):

respiratory bronchiolitis interstitial lung disease (J84.115)

Block J20-J22

Excludes2 (not included here):

chronic obstructive pulmonary disease with acute lower respiratory infection (J44.0)

Index terms for J21.9

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in J21

Frequently asked questions

What is ICD-10 code J21.9?

J21.9 is the ICD-10-CM code for acute bronchiolitis, unspecified, in the block J20-J22 (Other acute lower respiratory infections).

Is J21.9 a billable code?

Yes. J21.9 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does J21.9 belong to?

It belongs to category J21 – Acute bronchiolitis.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.