Canon-McMillan Junior High became the grades 6–8 Canonsburg Middle School in 1983, and would see its first and only complete renovation the next year, in 1984. This project remodeled the structure's entire interior (with the exception of the auditorium, which is historically preserved), and updated electrical and plumbing work to meet the safety codes of the time. Computer labs and a large group instruction room were added in the 90s, however the latter has since been removed and permanently divided into three classrooms. 6th grade was removed from CMS in 2002. The school saw minor security upgrades near the main entrance in 2014, however, CMS is now slated to close in the coming years as the building's structural and physical condition is deteriorating, and having not seen a full renovation since the 80s, the school is extremely dated inside. Cracks and chips have formed in staircases and floor tiles over the years, mostly due to old age and prolonged wear and tear.