He previously served on the Philadelphia Court of Common Pleas in the First Judicial District of Pennsylvania.

McKee received a Bachelor of Arts degree from the State University of New York at Cortland in 1969 and earned his Juris Doctor from Syracuse University College of Law where he was an honor student graduating in 1975 magna cum laude and as a member of the Order of the Coif and the Justinian Honor Society.

President Bill Clinton nominated Judge McKee to the United States Court of Appeals for the Third Circuit on March 22, 1994, to a seat vacated by Judge A. Leon Higginbotham Jr. McKee was confirmed by the United States Senate on June 8, 1994, and received his commission on June 9, 1994.

[3][4] In July 2018, McKee wrote for a unanimous panel when it upheld a Boyertown Area School District policy guaranteeing transgender students use of their preferred locker room.

[3] McKee is an elected member of the American Law Institute and serves as an Adviser on ALI's project to revise the Sentencing provisions of the Model Penal Code.