In asthma, healthcare utilization is frequently an outcome measure and can come from several sources. Asthma-related hospitalizations, emergency department (ED) visits, oral steroid bursts, and outpatient visits were compared between caregiver report and administrative data over 2 years. The difference between sources (caregiver minus administrative) was as follows: hospitalizations = -0.02 (95% limits of agreement, -0.66 to 0.61), ED visits = 0.18 (-1.16 to 1.52), steroid bursts = 0.26 (-3.98 to 4.49), and outpatient visits = 0.29 (-6.10 to 6.64). The percent of individuals with disagreement between sources was hospitalizations = 6.1%; ED visits = 20.2%; steroid bursts = 34.3%; and outpatient visits = 83.6%. The data sources resulted in similar estimates on the population level; however, there were pronounced differences for outpatient visits on an individual level. Importantly, the individual level disagreement between the data sources could negatively affect the perceived quality of care provided by a physician and reduce their compensation in a pay-for-performance system when physicians are rated using administrative data, yet they provide treatment based on patient-reported information.