Brewster left the show during its seventh season last year. She joined the show in season 2, and played Prentiss for six years as a supervisor for the Behavioral Analysis Unit.
"Our 200th episode is going to be a special show," showrunner Erica Messer said. "We can't imagine telling this story without Paget being present."
Paget had previously hinted that she might return in the future, especially since her character did not die in her last episode.
The episode featuring her return will air in February, as part of the ninth season that started airing Wednesday.