Air medical services are an essential component in the emergency response and critical care medical transport systems worldwide. Rotor-wing medical helicopters and fixed-wing aircraft transform the geography of time-dependent disease, especially for rural populations. Despite substantial evidence of outcome benefit to both patients and the health care system through improved access provided by air medical services, helicopter emergency medical services remains controversial in the United States. Continued debates on costs, safety, variation in performance, uneven emergency medical services system integration, regulatory alignment, and over-triage and use due to the uncertainty of occult injury challenge emergency and critical-care physicians referring patients for transport. Emergency medical services physicians tasked with direct or indirect oversight of air medical resources must understand the fundamental elements of air medical services including system design and integration, basic flight physiology, aircraft performance capability for both scene and inter-hospital transport, transport clinician capability, and the regulatory environment. Through careful use and integration, emergency medical services physicians can substantially extend the reach of time-critical interventions, improve access to specialized care, and minimize vulnerable out-of-hospital time for patients needing interhospital transfer.