ICD-10 Code J45.901 – Unspecified asthma with (acute) exacerbation (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J45.901 – Unspecified asthma with (acute) exacerbation
What it is
This code identifies asthma that is currently flaring up, but the record does not specify the asthma type or severity. Use it when the documentation clearly states an acute exacerbation and does not provide a more specific asthma code.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include wheezing, shortness of breath, cough, chest tightness, and increased work of breathing during an asthma flare.
When to use this code
Use J45.901 when the provider documents “asthma exacerbation,” “acute asthma,” or a similar flare and no more specific asthma subtype is recorded. It also fits when the chart confirms asthma worsening but leaves the asthma category unspecified. If the note includes a more specific asthma diagnosis, code that instead.
Do not use for
Do not use this code for asthma without an exacerbation, or when the documentation supports a more specific asthma code. Check documentation if the record describes status asthmaticus or another distinct asthma presentation.
Coding tip
Code the highest level of specificity documented, and query for asthma type if the note only says “asthma flare.”