MEDNAX is an American company founded in 1979 and is headquartered in Sunrise, Florida. The company focuses on neonatal, anesthesia, maternal-fetal and pediatric physician subspecialty services in all 50 states and Puerto Rico. The company currently operates in one primary line of business, staffing neonatologists, both in-office and in the hospital, through the business name Pediatrix Medical Group. Pediatrix was established in 1979, and is the United States' largest provider of newborn hearing screening. MEDNAX is a national medical group comprising providers of neonatal, anesthesia, maternal-fetal and pediatric physician subspecialty services. Pediatrix Medical Group, a division of MEDNAX , was founded in 1979 and includes neonatal physicians who provide services at more than 360 neonatal intensive care units, and collaborate with affiliated maternal-fetal medicine, pediatric cardiology, pediatric critical care and other physician subspecialists to provide a clinical care continuum.