According to ESPN's Adam Schefter, the deal will be for two years and $9 million.
Schaub, 35, spent the last three seasons as a backup quarterback with the Oakland Raiders, Baltimore Ravens and Falcons. After serving as the Houston Texans starting quarterback for parts of seven seasons, Schaub has started just two games since the start of the 2014 season.
Overall, he's thrown for 24,867 yards, 133 touchdowns and 90 interceptions in 145 career regular-season games. He was a Pro Bowl selection in both 2009 and 2012 and has thrown for over 4,000 yards three times in his career.
While Schaub is no longer an NFL starter, he's a nice backup for Matt Ryan and will provide veteran leadership for the Falcons once again. The fact he has extensive starting experience and is unlikely to be flustered if called upon to start games at some point during the season is also a solid trait to have in a backup quarterback.
Schaub's signing won't exactly cause a celebration in Atlanta, but it was a nice move all the same.