Underwood was chosen for the Gene Weed Special Achievement Award, which acknowledges unprecedented, unique and outstanding individual achievement in country music.
The Career Achievement Award will go to Keith and Milsap, as well as Steve Buchanan, the president of Opry Entertainment Group.
Rascal Flatts will be honored with the Jim Reeves International Award, which is presented to an artist for outstanding contributions to the acceptance of country music throughout the world.
The special awards are scheduled to be presented to the artists Sept. 9 at the Ryman Auditorium in Nashville.
[Academy of Country Music]
Notable deaths of 2014 [PHOTOS]