Quality measures play a prominent role in the US health care system. They are used to monitor and report performance across health plans, providers, and health systems and are a foundational element of value-based payment. Measuring the quality of asthma care has been challenging because of a lack of reliable data to assess clinical processes and track patient-specific outcomes. Existing asthma Healthcare Effectiveness Data and Information Set measures rely on administrative claims–derived data on dispensed medications. These are proxy measures of appropriate prescribing but are not reflective of comprehensive asthma care. The increase in the volume and specificity of longitudinal clinical data in electronic health records, movement toward electronic quality measures, and advances in electronic clinical data systems enable the development of more meaningful measures. A patient-reported measure of asthma control would incorporate key clinical indicators such as a validated age- and culturally appropriate test, and would reflect the combined outcome of medical management, self-management education, reduction of environmental exposures, and appropriate support services. Although there is a current quality measure that includes a test of asthma control (the Optimal Asthma Control Measure), work is needed to address questions about usability, patient literacy, and the influence of setting on self-reported scores. Comprehensive reliability and validity testing of both clinical data and stratification across risk groups will be needed to determine whether a measure based on standardized assessments of asthma control indeed promote improved clinical outcomes.