For patients with persistent asthma, inhaled corticosteroids (ICS) are a mainstay of controller therapy. These medications are usually prescribed to be taken daily and have been shown to be associated with decreased asthma morbidity. Adherence to daily treatment is very low in many populations in the United States. The purpose of this study is to evaluate the seasonal use of ICS prescription filling as reactive behavior primarily after an asthma exacerbation in a pediatric population. The study population is a subgroup of the Tennessee Asthma and Bronchiolitis Study. The children in this study were enrolled in Tennessee Medicaid (TennCare). The subjects had asthma and were 6 to 9 years of age during the years 2005 to 2010. Prescription filling was determined using claims data, and asthma exacerbations were defined by use of systemic rescue corticosteroids (RCS). In this cohort of 13,114 children with asthma, ICS and RCS filling were highly seasonal and trended with fall and winter peaks in asthma exacerbations. Prescription refilling was very low, with an average of three ICS fills per child who filled at least one during the study period. Among these children, 54.1% (7,096) had an asthma exacerbation during the study period. Among ICS users, 68.5% (3,441/5,020) had a disease exacerbation. ICS filling occurred overwhelmingly on the same day as RCS fills. The seasonal filling patterns of ICS coincide with asthma exacerbations. ICS adherence is low and inconsistent in this population of children with asthma. Increased adherence to ICS, particularly before the seasonal virus epidemics, could greatly reduce asthma morbidity.