The Flyers announced Monday that Mason was inked to a one-year deal for next season worth $1.5 million US.
The Oakville, Ont., native was set to be a restricted free agent this summer after earning nearly twice that amount in each of the last two seasons.
After winning the Calder Trophy as NHL rookie of the year with 10 shutouts and a 2.29 goals-against average with Columbus in 2008-09, Mason has struggled to maintain consistency over the succeeding 3 ½ seasons.
He was dealt at the NHL trade deadline last week in a deal that saw veteran Michael Leighton head to the Blue Jackets.
Mason relieved Ilya Bryzgalov in Saturday's loss to Winnipeg, stopping all nine shots he faced.
For the season, Mason has a 2.87 goals-against average and a .901 save percentage.