Entertainer of the Year will be decided between Stapleton, Eric Church, Luke Bryan, Luke Combs and Rhett.
Album of the Year nominees are Bryan's Born Here Live Here Die Here, Kane Brown's Mixtape Vol. 1, McBryde's Never Will, Brothers Osborne's Skeletons and Stapleton's Starting Over.
Single of the Year nominees are Lambert's "Bluebird," Gabby Barrett's "I Hope," Carly Pearce and Lee Brice's "I Hope You're Happy Now," Ingrid Andress' "More Hearts Than Mine" and Morris' "The Bones."
Song of the Year nominees are Lambert's "Bluebird," McBryde's "One Night Standards," Old Dominion's "Some People Do," Stapleton's "Starting Over" and Morris' "The Bones."
A full list of nominees can be found on the official ACM website.
The 56th annual ACM Awards will be broadcast live from three venues in Nashville on April 18 at 8 p.m. EST on CBS. This marks the second year in a row that the ACM Awards are being held in Nashville. Keith Urban hosted last year's event in September.