Aria Health, formerly called Frankford Health Systems, is a healthcare system in Northeast Philadelphia and Lower Bucks County. It consists of three hospitals and a number of outpatient clinics. With 4,025 employees, Aria Health is the 14th largest private employer in the city of Philadelphia. Aria Health operates several residency training programs for osteopathic physicians (DO). The residencies are accredited by the American Osteopathic Association.