The care and transport of patients outside of the hospital is the responsibility of tens of thousands of professionals in over 2000 EMS agencies and even more first responder systems across the United States. EMS is one pillar of public health, and a key asset in the resilience of the public to natural or other disasters. EMS is on the frontline of emergency care for all conditions and is the first point of entry for many patients to emergency departments. We study how to optimally design and deploy EMS agencies, how clinical interventions can best impact patient outcomes, and how EMS personnel can optimally interface as part of integrated health care delivery systems.