Maine Medical Center delivers both primary and tertiary care in the city and its surrounding areas. As a 606-bed non-profit hospital, it employes a full range of primary care and specialty physicians and is a regional trauma center where cardiac surgery is also performed. The Internal Medicine department alone is staffed by over 150 board-certified internists, two-thirds of whom have subspecialty certification and are members of one of the fifteen divisions within the department. The Barbara Bush Children's Hospital is a children's hospital without walls and has over 70 board-certified pediatricians, half of whom have subspecialty certification. Hospital services include a 25-bed Neonatal Intensive Care Unit, 24-hour emergency room, rehabilitation services, AIDS consultation service, and over three dozen outpatient clinics. The hospital also serves as a regional renal and marrow transplant center.