There has been a transition in US firearm injuries from an epidemic phase (mid-1980s to early 1990s) to an endemic one (since the mid-1990s). Endemic US firearm injuries merit public health attention because they exact an ongoing toll, may give rise to new epidemic outbreaks, and can foster firearm injuries in other parts of the world. The endemic period is a good time for the development of ongoing prevention approaches, including assessment and monitoring of local risk factors over time and application of proven measures to reduce these risk factors, development of means to address changing circumstances, and ongoing professional and public education designed to weave firearm injury prevention into the fabric of public health work and everyday life.