"I'm thrilled to be going back to work with Conan, and very excited to start a whole new venture on TBS. However, I am mostly looking forward to getting out of the house again," Richter said in a statement Tuesday.
Richter, who served as O'Brien's sidekick at the beginning of Late Night with Conan O'Brien, departed for his own projects in 2000. After Andy Richter Controls the Universeand Andy Barker, P.I.both failed, Richter, 43, returned when O'Brien took over the Tonight Show in 2009.
Conan's shticky response to the announcement that his old sidekick would be back for his new show, Conan: "This decision was made without my authority. I will get to the bottom of this."
The comedic team began in 1993 when Richter joined O'Brien, who was plucked from obscurity to replace Letterman on NBC.
Conan premieres Monday, Nov. 8 at 11/10c on TBS.