The deal is worth $8.5 million, with a maximum value of $12 million and includes $5 million in guaranteed money.
Umenyiora, 31, spent the first nine seasons of his career with the New York Giants helping the team win two Super Bowl Championships.
"There was nothing better than to be able to win (in New York)," Umenyiora said last week, according to The Atlanta Journal-Constitution. "The only thing I can think of that would be better than being able to win in New York would be to be able to win here in Atlanta. We'll see how that plays out. Hopefully, it works out in a positive direction."