Envision Healthcare Holdings, Inc., is a provider of physician-led, outsourced medical services in the United States. The Company conducts its business primarily through two operating subsidiaries, EmCare Holdings, Inc. (EmCare) and American Medical Response, Inc. (AMR). The Company markets its services primarily under the EmCare and AMR brands. EmCareis a provider of integrated facility-based physician services, including emergency, anesthesiology, hospitalist/inpatient care, radiology, tele-radiology and surgery. EmCare also offers physician-led care management solutions outside the hospital. AMR is a provider and manager of community-based medical transportation services, including emergency (911), non-emergency, managed transportation, fixed-wing air ambulance and disaster response. The Company, through VISTA Staffing Solutions Inc, provides physician staffing services.