The University of Pennsylvania Health System has sold Mill Creek School in West Philadelphia to Public Health Management Corp. (PHMC), an acquisitive Philadelphia nonprofit that provides a wide range of health and social services.

PHMC declined to disclose the price and the number of people who work at Mill Creek. The sale was effective April 2.

The school at 111 N. 49th St. now serves 30 children in grades seventh through 12th who have personal, emotional, and educational challenges, according to PHMC. The school was founded in 1971 as part of the Institute of Pennsylvania Hospital. Penn acquired Pennsylvania Hospital in 1997.

Pennsylvania Hospital sold the affiliated behavioral health operation in West Philadelphia in 1996 but continued to run the school through the Hall-Mercer Community Behavioral Health Center of Pennsylvania Hospital.

Mill Creek School was originally called the High School of the Institute of the Pennsylvania Hospital, according to the Asylum Projects website.

“The Mill Creek School complements PHMC’s robust special education and educational support programs,” said Richard J. Cohen, president and chief executive of PHMC, which employs more than 3,500.

In February, PHMC acquired the Center for Autism.