Murphy told The Hollywood Reporter Wednesday the trio's popular characters will graduate at the end of the upcoming third season, which is to begin in September.
"You can keep them on the show for six years and people will criticize you for not being realistic, or you can be really true to life and say when they started the show they were very clearly sophomores and they should graduate at the end of their senior year," Murphy told the entertainment industry trade newspaper. "We made that decision and I involved Chris and Lea and they thought that was a good idea. They both trust the writing and trust me and felt that it would be great to have an open and closed experience for them to go out while they were on top."
Murphy said he has not yet discussed the move with Monteith.
Michele, Monteith and Colfer are all in their 20s in real life.