Jayma Mays joins new CBS comedy "The Millers"

Actress Jayma Mays arrives for the 19th Screen Actors Guild Awards on Jan. 27, 2013, at the Shrine Auditorium in Los Angeles.

"Glee" star Jayma Mays is branching out from the halls of McKinley High.

The actress has been cast in the new CBS comedy "The Millers," the network confirmed.

She will portray Debbie, the sister of Nathan Miller (Will Arnett) in the upcoming series, premiering this fall. Arnett, meanwhile, will portray a recently divorced news reporter looking forward to living the singles' life until his parents' marital problems unexpectedly derail his plans.

Mays replaces "It's Always Sunny in Philadelphia" actress Mary Elizabeth Ellis, who appeared in "The Millers" pilot. Mays' character, who has two children, is surprised to discover that her parents are splitting up and attempts to help her father get through it. "The Millers" will also feature Beau Bridges and Margo Martindale.

Mays has appeared as guidance counselor Emma Pillsbury on "Glee" since the show's start in 2009. It's unclear what kind of role Mays will play in the upcoming season of the Fox comedy, which is losing some main actors, including Heather Morris (Brittany), Mark Salling (Puck), Harry Shum Jr. (Mike) and Amber Riley (Mercedes).

In March, Mays told CBSNews.com about what "Glee" meant to her: "I think it's a show that's so amazing and different and creative and special, but you never know when you're making something how people are going to perceive it, or if they're going to get it, or like it. I think from the start we knew we were doing something different and it was at least special to us. So the fact that people have loved it and people are still watching is really wonderful."

"The Millers" premieres Sept. 26 at 8:30 p.m. ET on CBS.