ICD-10 Code J45.5 – Severe persistent asthma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J45.5 – Severe persistent asthma
What it is
J45.5 identifies severe persistent asthma, a chronic inflammatory airway disease with ongoing symptoms and frequent airflow limitation. Use it when the record clearly documents this severity level.
Clinical signs
Clinical features vary; refer to documentation. Common findings include frequent daytime symptoms, nighttime awakening, and reduced activity tolerance, with persistent bronchial obstruction or recurrent exacerbations.
When to use this code
Use J45.5 when the provider documents severe persistent asthma, or when the chart clearly supports that severity classification. It may appear in outpatient, inpatient, or emergency records as the principal asthma diagnosis or a relevant comorbidity. Check documentation if severity is unclear or if another asthma type is specified.
Do not use for
Do not use this code for mild, moderate, intermittent, or unspecified asthma. If the record describes an acute exacerbation without severity documentation, code the documented asthma type and confirm the correct specificity.
Coding tip
Code the highest documented asthma severity exactly as stated, and query the provider if “severe” is implied but not clearly documented.