Stefani will return to the show where she met her boyfriend Blake Shelton for Season 12, which will start in February. Shelton, Adam Levine and Alicia Keys will return as coaches, and Carson Daly will return as host.
Cyrus is out for Season 12, but she'll be back as a coach for Season 13, which will begin next fall. The full coaches' roster will be announced at a later date.
"We can't wait to experience the unique chemistry and energy Gwen, Alicia, Blake and Adam will bring to season 12," NBC Entertainment reality boss Paul Telegdy said in a statement. "With Miley returning for season 13, we're truly ecstatic about the unmatched musical know-how and talent coming together in our coming seasons."
Season 11 is currently in progress.
The Voice airs Mondays and Tuesdays at 8/7c on NBC.