ICD-10 Code J45.4 – Moderate persistent asthma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J45.4 – Moderate persistent asthma
What it is
J45.4 identifies moderate persistent asthma, a chronic inflammatory airway disorder with ongoing symptoms that are more frequent than mild asthma. Use it when the documentation clearly states moderate persistent asthma.
Clinical signs
Patients typically have recurring wheeze, cough, chest tightness, and shortness of breath with persistent day-to-day impairment. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents moderate persistent asthma as the diagnosis. It may appear in outpatient, emergency, or inpatient records when asthma severity is specified. If the note only says asthma, check documentation for the severity level before coding.
Do not use for
Do not use J45.4 for mild, severe, or intermittent asthma, or when asthma severity is not documented. Check documentation if the record describes an acute exacerbation without a persistent asthma severity statement.
Coding tip
Code the documented severity exactly; if the note is unclear, query the provider rather than assume moderate persistent asthma.