ICD-10 Code J45.3 – Mild persistent asthma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J45.3 – Mild persistent asthma
What it is
Mild persistent asthma is a chronic asthma pattern with symptoms that occur more than twice weekly but not daily. Use this code when the record clearly documents mild persistent asthma without a more specific subtype.
Clinical signs
Typical features include recurrent wheeze, cough, chest tightness, or shortness of breath with ongoing airway inflammation. Clinical features vary; refer to documentation for the pattern and severity.
When to use this code
Use J45.3 when the provider documents mild persistent asthma or describes a persistent asthma pattern consistent with that severity. Apply it for outpatient, inpatient, or encounter coding when the diagnosis is confirmed in the record. If the note only says “asthma,” check documentation for severity.
Do not use for
Do not use this code for intermittent asthma, moderate or severe persistent asthma, or an acute exacerbation unless those are specifically documented. Do not assume severity from medication use alone.
Coding tip
Code the documented asthma severity exactly as stated, and query the provider if the record does not support mild persistent asthma.