Asthma affects more than 15 million people in the United States. Inhaled corticosteroids (ICS), the ranking treatment-of-choice, are safe and highly efficacious in controlled trials, but adherence to ICS medications in real-world settings is poor in all patient groups, especially low-income and minority patients who experience the most morbidity from asthma. Children and adults with asthma take less than half of their prescribed ICS medication. One study found that only 44% of ICS prescriptions for children with asthma were filled. Even the most effective medications have little value if not taken as prescribed. Decreasing use of ICS has been repeatedly linked to poor asthma control and increasing health care utilization.