Show Shakeup! Bristol Palin Joining 'Teen Mom OG' Cast

Bristol Palin is headed to Teen Mom OG.

RadarOnline.com can confirm the most famous teen mom there is will be joining the MTV reality show next season.

Sarah Palin’s daughter was just 17 when she had her first kid, Tripp, with ex-fiancé Levi Johnston in December 2008.

Just three months later, Palin and Johnston ended their engagement.

Bristol went on to marry Dakota Meyer, a former Marine and Medal of Honor recipient whom she is now divorcing. The now 27-year-old added two more children to her brood with Meyer — Sailor Grace and Atlee Bay.

Sources reveal Sarah Palin's daughter will take fired Farrah Abraham's place on the hit series.

Bristol will make number five in the cast alongside Amber Portwood, Mackenzie McKee, Maci Bookout and Catelynn Lowell.

It seems the cast is blindsided by the move. Sources tell RadarOnline.com the other girls didn't see this coming, and even Teen Mom 2 star Kail chimed in on Twitter, questioning the producers motives. "Our producers sure know what to do," she wrote with a worried face emoji.