Ross is making $1.6 million this year in the final season of a $3 million, two-year deal. The extension announced Tuesday will pay him $1,625,000 in each of the 2011 and 2012 seasons.
He can make an additional $250,000 annually in performance bonuses: $50,000 each for 50, 60, 70, 80 and 90 games started as a catcher.
Ross was batting .269 with no homers and 18 RBIs heading into Atlanta's game at the Washington Nationals on Tuesday night. The 33-year-old is in his ninth major league season and had thrown out 37 percent of runners who've tried to steal on him.
He could have become a free agent at the end of this season.
McLouth is hitting .168 with three homers and 14 RBIs this season. Clevlen went on the DL in May with a sprained toe.