Measurement of outcomes after surgery and transcatheter valve interventions have become standard for quality assessment, performance improvement, and comparative effectiveness reporting and research. Public reporting of procedural outcomes has also become required in some states and is increasingly performed nationally. Initially, hospital performance measurement of outcomes after cardiac surgical procedures were limited to in-hospital mortality and major morbidity rates, because the data were readily available, relatively complete, and not overly burdensome for sites to collect. However, it soon became apparent that capturing in-hospital mortality and complication rates alone was not truly reflective of procedural outcomes, with up to one-third of periprocedural mortality occurring after hospital discharge but before 30 days. Hence, professional society–based clinical registries changed the main outcome performance metric to operative mortality and included any death that occurred during the initial hospital stay, independent of time, and any death within 30 days, independent of location.1 This hospital performance metric more accurately reflected the true outcomes after surgery and minimized the possibility of gaming reporting, but it did add a considerable burden of data collection to hospitals. Thus, 30-day mortality and major morbidity rates have become the foundation of procedure risk models and are the basis for the Society for Thoracic Surgeons’ 3-star hospital rating of cardiac surgery performance.