According to Entertainment Weekly, Adrianne Palicki will reprise her role as Tyra in the final two episodes, while Taylor Kitsch will return as Tim for the last four.
Zach Gilford, who played Matt, has also confirmed that he will return for four episodes, with two airing in the middle of the season and two at the end.
Gilford added that he expects the fifth season to be the show's last, saying: "To my knowledge, it's pretty much done and they're writing an ending to the show. I know a lot of people were not satisfied with the Lost finale - but I think it's nice when they can write towards a [series finale]. If you have a finite amount of episodes then you can come up with a satisfying ending."
Jesse Plemons, who played Landry, is thought to be in talks to return to the show while Scott Porter has already signed a deal to return as Jason in an episode.