[1] The Pioneer Athletic Conference, then known as the PAC-8, was composed of the following charter members: Great Valley and Owen J. Roberts join the Pioneer Athletic Conference and bring the total membership to ten.
Great Valley left the PAC-10 to join the Southern Chester County League.
In the same year, the PAC-10 admitted Boyertown which effectively kept the Pioneer Athletic League at 10-member status.
St. Pius X and Kennedy-Kenrick Catholic High School in Norristown merged to form a new high school named Pope John Paul II, located in Royersford.
Beginning in August 2016, the Norristown Eagles and Upper Merion Vikings joined the PAC to make it a 12-team conference.