NASEMSO is a seamless nationwide network of coordinated and accountable state, regional and local EMS systems, using public health principles, data and evidence as a basis for safe and effective care in day-to-day operations as well as during catastrophic events. NASEMSO supports its members in developing EMS policy and oversight, as well as in providing vision, leadership and resources in the development and improvement of state, regional and local EMS and emergency care systems.