ICD-10-CM J21.9 is the diagnosis code for Acute bronchiolitis, unspecified. This code falls under the section "Other acute lower respiratory infections" within Chapter 10 — Diseases of the respiratory system (J00-J99). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as J21.9. They are mutually exclusive:
Understanding where J21.9 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, J21.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
J21.9 is the ICD-10-CM diagnosis code for "Acute bronchiolitis, unspecified". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of J21.9 is J21 ("Acute bronchiolitis"). J21.9 provides a more specific classification within this category.
J21.9 is located in Section J20-J22 — "Other acute lower respiratory infections" within Chapter 10 of the ICD-10-CM Tabular List.
Use J21.9 when the patients documented diagnosis matches "Acute bronchiolitis, unspecified" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Acute bronchiolitis, unspecified is J21.9.
Yes, J21.9 can be used as a primary diagnosis code since it is billable and specific.
J21.9 is in Chapter 10 of the ICD-10-CM Tabular List.
Type 1 Excludes for J21.9 include: chronic bronchiolitis (J44.89).
Yes, J21.9 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.