OBJECTIVES: Persistent asthma is a significant, understudied health condition leading to disproportionate use of health care resources and patient burden compared to patients with mild-to-moderate forms of the disease. . This study was designed to describe the population of individuals with persistent asthma and severe persistent asthma in the U.S., identify asthma medication use patterns, and examine the influence of patient characteristics on choice of treatment. METHODS: We used HEDIS criteria to identify individuals with persistent asthma in the 2011 Medical Expenditure Panel Survey. Asthma severity was assessed based on exacerbations and prescription medication use. Andersen’s behavioral model of health service use was used to identify predisposing, enabling, and need variables associated with persistent asthma and medication use. RESULTS: The persistent asthma population (n=566) was predominantly female (67.72%) and white (83.69%), with a mean age of 53.06 years. On average, they had 0.16 ER visits, 0.047 hospital stays, 0.18 outpatient visits, 1.47 office-based provider visits, and 10.32 prescription medication fills during the survey year. 2.3% of patients were identified as having severe persistent asthma. They were predominantly female (92%) and white (81.46%), with a mean age of 58.08 years. They had an average of 0.54 ER visits, 0.54 hospital stays, 0.154 outpatient visits, 3 office-based provider encounters, and 25.92 prescription medication fills during the survey year. 41.83% of the persistent asthma population were not prescribed a short-acting beta agonist, compared to 36.71% of the severe asthma population. 49.85% of the persistent asthma population was on an inhaled corticosteroid + long-acting beta agonist (ICS/LABA), per guideline recommendations. CONCLUSIONS: There appear to be patient characteristics that are associated with persistent asthma; however the lack sample size in the severe population limited results. A significant number of people were not treated according to guidelines, indicating a potential deficit in prescribing practices.