“The Hills: New Beginnings” is supposed to be a fresh start for some of the cast, but not everyone is returning. Lauren Conrad, Kristin Cavallari and Lo Bosworth will not appear on the show.

For Lauren and Lo, it’s about being in a different place in their lives. Lauren hasn’t commented on the reboot, but sources previously said she wishes the new cast the best.

Heidi Montag, who is starring in “New Beginnings” told Extra, “I think that she’s in a different place.”

Conrad runs fashion and home goods lines for Kohl’s in addition to her lifestyle website, her advice podcast and her nonprofit shop, The Little Market. She married musician William Tell in 2014 and gave birth to their first child, William “Liam” James Tell, in July 2017. She announced in April that she is pregnant again.

Lo Bosworth, meanwhile, told “Conversations with Maria Menounos” that she is grateful for the opportunity “Laguna Beach” and “The Hills” provided her, but she’s done. The founder of feminine hygiene company Love Wellness turned down an offer from the MTV reality show.

“For me, I’m just really not that interested in going down that rabbit hole. For me, being on reality TV was an interesting experience,” she told Menounos. “I am acutely aware of the platform it has provided me, and I feel extremely fortunate to have had the experience because I have this life now because of it. So … I don't know these people who are on the show…I know them, but I don't have relationships with any of them.”

Kristin Cavallari, meanwhile, isn’t against reality TV. In addition to running her shop “Uncommon James” and writing cookbooks, the mother of three has her own E! reality show, “Very Cavallari.”

Even though she isn’t camera shy, Kristin still isn’t so sure she could handle the environment on “The Hills: New Beginnings.”

“I would’ve loved to have made a cameo but I don’t think I could’ve gone back to that whole lifestyle,” she told HollywoodLife in March. "As a mom and as a wife — if it was just me and I just had myself to look after, but mentally and emotionally, I could not have gone back to that same place.”

So who is on “The Hills: New Beginnings”? First, there are returning cast members: Montag, Spencer Pratt, Audrina Patridge, Brody Jenner, Frankie Delgado, Jason Wahler, Justin “Bobby” Brescia, Stephanie Pratt and Whitney Port.

Then, there are the newbies. Some are expected editions. Several cast members are married, so Brody’s wife, Kaitlynn Carter, Frankie’s wife, Jennifer, and Jason’s wife, Ashley, are all onboard.

There are a couple of other new cast members too. Mischa Barton is best known for starring on Fox’s scripted drama, “The O.C.,” which inspired “Laguna Beach.” Now, she is starring in “New Beginnings.” Model/actor Brandon Lee, meanwhile, is the 23-year-old son of Pamela Anderson and Tommy Lee. It seems both knew the Jenner family before joining the show.

“Growing up, [Brandon] considered Brody an older brother and the two bonded over their similar Hollywood upbringing,” Nina L. Diaz, president of Entertainment for MTV, VH1, CMT & Logo, told the Hollywood Reporter.

“Mischa traveled in the same circles as our cast, and she and the Pratts go way back. She knew the Jenners growing up and in fact, has a close relationship to Brody’s mother Linda.”

“The Hills: New Beginnings” premieres Monday at 10 p.m. EDT on MTV.

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Lauren Conrad and Kristin Cavallari will not be on "The Hills: New Beginnings." Conrad (left) is pictured on Aug. 8, 2018 in New York. Cavallari is pictured on May 18, 2018 in New York. Cindy Ord/Getty Images for Kohl's; Kena Betancur/AFP/Getty Images