Area Ambulance Service is the regional 9-1-1 Emergency Medical Services provider for Cedar Rapids, Marion, and 15 surrounding communities. Covering 250 square miles, they respond to over 16,000 calls for service each year. In 2006, Area Ambulance Service separated from Mercy Medical Center incorporating as a 501(c)(3) not-for-profit organization. AAS is completely user fee-based and receives no tax subsidy or funding from any other source. Area Ambulance Service staffs 5-7 Advanced Life Support ambulances each day, all equipped with the latest in EMS technology. AAS meets strict response time guidelines; therefore, their 12-hour shifts are staggered and adjusted according to call demand.