Kenneth Thomas, 79, left Bonneville High School in Idaho Falls to enlist in the Marines Jan. 15, 1952, about halfway through his senior year, and later earned his GED, KIFI-TV, Idaho Falls, reported Wednesday.
Thomas, who served in the Korean War, said his daughter, Dorine, got in touch with Bonneville High principal John Pymm recently after he told her one of his biggest regrets was not graduating high school.
The pair did some research and soon discovered Thomas' work to get his GED while serving in the Marines actually qualified him for a high school diploma.
"We had actually received that information from the armed services indicating as much," Pymm said. "So there in our archives was the good news that he was actually a high school graduate."
Thomas is now scheduled to walk across the stage May 25 alongside Bonneville's 2013 senior class to receive his diploma.
"If my example would just touch one or two kids and make them stay in school, it would be worth it," Thomas said.