Urgent care is the delivery of ambulatory care in a facility dedicated to the delivery of unscheduled, walk-in care outside of a hospital emergency department. The initial urgent care centers opened in the 1970s. Since then this sector of the healthcare industry has rapidly expanded to an approximately 17,000 centers. Many of these centers have been started by entrepreneurial physicians who have responded to the public need for convenient access to unscheduled medical care. Other centers have been opened by hospital systems, seeking to attract patients. Much of the growth of these centers has been fueled by the significant savings that urgent care centers provide over the care in a hospital emergency department. Many managed care organizations (MCOs) now encourage their customers to utilize the urgent care option.