1. Supportive professional services other than room, board, and routine hospital services that are incidental to the hospital stay and provided by the facility such as ambulance, anesthesia, blood administration, drugs, laboratory tests, pharmacy, operating room, x-rays, medical, surgical, and central supplies; physical, occupational, and speech therapy; and inhalation therapies. Also called inpatient ancillary services. 2. In a medical office setting, ancillary medical services may consist of diagnostic tests such as x-rays or laboratory tests.