In the United States, emergency medical services (EMS) provide out-of-hospital acute medical care and/or transport to definitive care for those in need. They are regulated at the most basic level by the National Highway Traffic Safety Administration,[1] which sets the minimum standards that all states' EMS providers must meet, and regulated more strictly by individual state governments, which often require higher standards from the services they oversee.
Wide differences in population density, topography, and other conditions can call for different types of EMS systems; consequently, there is often significant variation between the Emergency Medical Services provided in one state and those provided in another.