The "Glee" cast will return for Season 4, but for how long?

According to The Hollywood Reporter, all 15 regular cast members -- Lea Michele, Cory Monteith, Chris Colfer, Matthew Morrison, Jane Lynch, Jayma Mays, Naya Rivera, Heather Morris, Kevin McHale, Darren Criss, Amber Riley, Jenna Ushkowitz, Dianna Agron, Mark Salling and Harry Shum Jr. -- will return to the Fox musical series. However, the episode count for each remains undetermined and should allow the cast to explore other projects.

THR reports Chord Overstreet is in talks to be added as a series regular. Overstreet joined the series during Season 2, left at the end of the season after being passed up for regular status and returned in a recurring role during Season 3.

Series co-creator Ryan Murphy said he extended invites to the entire cast to return. "We've become like a family," he told Vulture. "I said to them anybody who wants to stay on the show will stay on the show. I asked all of them, 'What do you want to do? What are you interested in doing?'"

Season 4 will see guest appearances by Kate Hudson and Sarah Jessica Parker. Hudson will play Rachel's (Lea Michele) dance instructor and Parker is playing a manager of sorts to Kurt (Chris Colfer). "American Idol" runner-up Jessica Sanchez is also rumored to appear in multiple episodes.

"Glee" returns to Fox in its new timeslot, Thursdays at 9 p.m. ET, on Thurs., Sept. 13.

Re-live "Glee" Season 3 by clicking through the slideshow below.

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  • "The Untitled Rachel Berry Project"

  • "The Untitled Rachel Berry Project"

  • "The Untitled Rachel Berry Project"

  • "The Untitled Rachel Berry Project"

  • "The Untitled Rachel Berry Project"

  • "Old Dog New Tricks"

  • "Old Dog New Tricks"

  • "Old Dog New Tricks"

  • "Back-Up Plan"

  • "Opening Night"

  • "Opening Night"

  • "Opening Night"

  • "Tested"

  • "Tested"

  • "Bash"

  • "New Directions"

  • "New Directions"

  • "New Directions"

  • "New Directions"

  • "New Directions"

  • "New Directions"

  • "100"

  • "Trio"

  • "Trio"

  • "Frenemies"

  • "Frenemies"

  • "Previously Unaired Christmas"

  • "Puppet Master"

  • "Puppet Master"

  • "Puppet Master"

  • "Puppet Master"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "The End Of Twerking"

  • "Glee" Season 5 Cast

  • "A Katy or a Gaga"

  • "A Katy or a Gaga"

  • "A Katy or a Gaga"

  • "A Katy or a Gaga"

  • "A Katy Or A Gaga"

  • "A Katy Or A Gaga"

  • "A Katy Or A Gaga"

  • "A Katy Or A Gaga"

  • "A Katy Or A Gaga"