Mass shootings in the US have changed how we live in and think about our society. Already in 2019, there have been more than 290 mass shootings—defined as the injuring or killing of four or more people; and all schools now conduct "active shooter" lockdown drills. Gun violence is a national health crisis that many medical professionals view as an epidemic that must be confronted with funding and data-driven policy. How can doctors, administrators, researchers, and their institutions—as well as governing organizations—have a greater impact on reducing this painful and chronic American disease?