CARES—the Cardiac Arrest Registry to Enhance Survival—was established by the U.S. Centers for Disease Control and Prevention and Emory University to improve survival from out-of-hospital cardiac arrest (OHCA) in the United States. Communities that join CARES commit to entering cardiac arrest data from EMS agencies and hospitals into a national database in order to track their performance confidentially over time and improve the quality of patient care—and ultimately prevent needless deaths. By joining CARES, communities gain more than just access to information that will help them improve performance and save lives. They also contribute to one of the largest EMS registries in the world, and one of the few that also includes patient outcome information from hospitals. Those features enable CARES data to be used to conduct vital research that furthers our knowledge of cardiac arrest treatment and saves countless lives for years to come.