From the AJC.com:
MARTA tokens, which had already gone the way of the Susan B. Anthony coin, will soon be worthless. Though it stopped issuing the coins three years ago, MARTA still accepted them at vending machines in exchange for Breeze cards. That ends after Sept. 30.
Until then, customers can also exchange their tokens at the Lenox, Lindbergh, Five Points and airport rail stations in exchange for MARTA trips.