The shows have been shut down since the Writers Guild of America went on strike Nov. 5 against the Alliance of Motion Picture and Television Producers.
The WGA announced Friday it has reached an independent agreement with Letterman's Worldwide Pants production company, which will allow the two late-night talk shows to get back to work with their guild-covered writing staffs.
"This is a comprehensive agreement that addresses the issues important to writers, particularly new media. Worldwide Pants has accepted the very same proposals that the guild was prepared to present to the media conglomerates when they walked out of negotiations on Dec. 7," the WGA said in a statement on its Web site Friday.
"Today's agreement dramatically illustrates that the Writers Guild wants to put people back to work, and that when a company comes to the table prepared to negotiate seriously, a fair and reasonable deal can be reached quickly."
"We're happy to be going back to work, and particularly pleased to be doing it with our writers," Letterman said in a statement, Variety.com reported. "This is not a solution to the strike, which unfortunately continues to disrupt the lives of thousands. But I hope it will be seen as a step in the right direction."