Air ambulance or medical evacuation (MEDEVAC) services in Canada are typically operated by third parties including non-governmental organizations and private contractors working on behalf of a provincial health authority, with a mix of fixed wing and rotary wing (Helicopter Emergency Medical Service or HEMS) fleets in use. They play a major role in Canadian healthcare given the massive geographic barriers to access. The two largest providers are Ornge Air Ambulance in Ontario, which operates twelve bases across the province, and STARS Air Ambulance, which operates six bases across Alberta, Saskatchewan, and Manitoba.