2026 ICD-10-CM Diagnosis Code J21Acute bronchiolitis

ICD-10-CM CodesJ00–J99J20-J22J21

ICD-10-CM J21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J21 is a non-billable ICD-10-CM category code for acute bronchiolitis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as J21.0, J21.1, J21.8, and J21.9.

Code Identity

ICD-10-CM Code
J21
Billable Status
No — Non-Billable Category
Code Describes
Acute bronchiolitis
Chapter
J20-J22
Other acute lower respiratory infections

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ20-J22Other acute lower respiratory infections
CategoryJ21Acute bronchiolitis
This CodeJ21Acute bronchiolitis

Specific Coding for Acute bronchiolitisOverview

Non-specific codes like J21 require more characters. Use one of these billable codes instead:

  • Use J21.0 for Acute bronchiolitis due to respiratory syncytial virus

  • Use J21.1 for Acute bronchiolitis due to human metapneumovirus

  • Use J21.8 for Acute bronchiolitis due to other specified organisms

  • Use J21.9 for Acute bronchiolitis, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • acute bronchiolitis with bronchospasm

Type 2 Excludes

  • respiratory bronchiolitis interstitial lung disease J84.115

Clinical InformationClinical

  • Acute Bronchiolitis

    acute inflammation of the bronchioles usually caused by the respiratory syncytial virus.

Patient EducationClinical

Bronchial Disorders

When you breathe in, the air travels down through your trachea (windpipe). It then goes through two tubes to your lungs. These tubes are your bronchi. Bronchial disorders can make it hard for you to breathe.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About J21Overview

Is J21 (Acute bronchiolitis) a billable code?

No. This is a category header that groups the codes for acute bronchiolitis, and headers cannot be submitted on claims. Claims for acute bronchiolitis need a more specific code from this category, such as J21.0, J21.1, and J21.8.