ICD-10 Code J45.51 – Severe persistent asthma with (acute) exacerbation (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J45.51 – Severe persistent asthma with (acute) exacerbation
What it is
This code identifies severe persistent asthma that is currently flaring up. Use it when the record shows a severe baseline asthma pattern plus an acute worsening episode.
Clinical signs
Clinical features vary; refer to documentation. Common findings include wheezing, cough, chest tightness, shortness of breath, and increased work of breathing during an asthma exacerbation.
When to use this code
Use J45.51 when the provider documents severe persistent asthma and states there is an acute exacerbation. It fits encounters for worsening asthma symptoms requiring evaluation, monitoring, or escalation of care. If severity or exacerbation is not clearly documented, check documentation.
Do not use for
Do not use this code for asthma without an acute exacerbation, or when the severity is not documented as severe persistent. If the chart only says asthma attack or wheezing, check documentation.
Coding tip
Verify both elements in the note: severe persistent asthma and acute exacerbation; if either is missing, choose a more specific or supported code.