Children’s Hospital of Orange County (CHOC) is a children's hospital located in Orange County, California. Its main hospital is located in the City of Orange and it operates the pediatric care at Mission Hospital (a hospital-within-a-hospital) in nearby Mission Viejo. The combined operation of CHOC (Orange) and CHOC (Mission) ranks as the 15th busiest children’s hospital in the country. It also prides itself as having one of the busiest pediatrics residency programs in the region.