ICD-10 Code J45.42 – Moderate persistent asthma with status asthmaticus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J45.42 – Moderate persistent asthma with status asthmaticus
What it is
This code identifies moderate persistent asthma when the patient is in status asthmaticus, meaning a severe asthma flare that does not quickly improve. Use it for documented moderate persistent asthma with an acute status asthmaticus episode.
Clinical signs
Typical findings include worsening wheeze, shortness of breath, chest tightness, and cough that are consistent with an asthma exacerbation. Clinical features vary; refer to documentation.
When to use this code
Use J45.42 when the record clearly states moderate persistent asthma and status asthmaticus together. It fits encounters for severe asthma flare-ups that require assessment and monitoring, not routine asthma follow-up. If the note only says asthma exacerbation without severity or status asthmaticus, check documentation.
Do not use for
Do not use this code for asthma without status asthmaticus, or when the severity is not documented. Check documentation if the record instead describes mild, mild persistent, or severe persistent asthma.
Coding tip
Assign J45.42 only when both the asthma severity and status asthmaticus are explicitly documented.