Financial pressures exerted by managed care organizations toward hospitals to improve efficiencies and to lower total healthcare costs continue to force physicians and administrators to reevaluate operations and practices. This shifting of risk exposure from insurers to providers has resulted in many mergers, acquisitions, and affiliations, so as to form integrated health systems that reduce repetition and duplication of services. Therefore, as these integrated systems develop, along with the emergence of tertiary care, regional referral, and specialty hospitals, the need for patient transfers between such facilities will expand. The decision to move patients between facilities is a multicomponent process comprising health, safety, financial, and legal concerns. Interfacility transportation of patients has been performed over the past 20 to 30 years. Whereas ground transport services were prominent in the 1970s, air medical programs using helicopters and fixed-wing aircraft have recently become widespread. Both hospital-based and private agencies have continued to develop programs for efficiently and expeditiously transporting critically ill or injured patients, many requiring complex life-support devices. The Practice Management Committee of the American College of Emergency Physicians recently updated the 1990 policy statement on interfacility transfers, and two position statements are available from the National Association of EMS Physicians on criteria for air medical transport and medical direction for interfacility transport services. This review provides an overview of transportation systems and services available and assists physicians in understanding the various modes and characteristics of systems available. Personnel configurations and capabilities, physiological limitations, inherent requirements for equipment and patient preparation, and legal issues involved with transferring patients are also outlined.