Founded in 1855, CHOP is the nation’s oldest hospital dedicated solely to the care of children. The Main Hospital has 500 beds, 40 percent of which are allocated to intensive care with over 24,000 inpatient admissions per year. CHOP is the community hospital and primary care center for children in West and South Philadelphia, and a major tertiary referral center for the greater Delaware Valley area with an estimated population of 10 million. CHOP serves a diverse population of children that includes large numbers of racial and ethnic minorities, healthy newborns, infants, children and adolescents. CHOP provides primary care through its extensive network of 31 Primary Care Centers, which care for ~250,000 patients per year, located in Philadelphia, southern New Jersey, and northern Delaware. The CHOP primary care network is organized as a practice-based research network called PeRC, which receives institutional infrastructure support for recruitment into projects. Ten large Specialty Care Centers provide a comprehensive range of outpatient subspecialty services in locations throughout the metropolitan area. Overall, there are nearly 2 million patient visits made to CHOP by 400,000 unique patients. The CHOP Emergency Room manages >90,000 patient visits per year.