The "What's Left of Me" singer, 40, will take over when the program picks up again this spring. "He'll be a great fit," one source says. There's no word yet on whether his stint will extend beyond the upcoming season, but the source adds, "He's happy to be on board."
The show could mean big changes for the former Sing Off host's family. The insider tells Us that Lachey, who has said he and wife Vanessa want to raise son Camden in Cincinnati, plans to rent a place in New York City, where Buzz films.
Keagan, who helped launch Buzz in 2011 and filmed more than 400 live episodes, taped her last show on Dec. 20, 10 days before announcing that she would not return.
"I've had the most wonderful time and experience hosting Buzz, and I am very grateful to have worked with the stellar production team behind the show, as well as Tom Calderone and Lee Rolontz at VH1, who were incredible champions and supporters," she said in a statement to Deadline on Dec. 30.
She added: "I'm sad to leave but I am very proud to have helped launch VH1's first morning show and look forward to its continued success."
Prior to Keagan's departure, Big Morning Buzz Live was co-hosted by Australian TV personality Jason Dundas. There's no word yet on who will star opposite Lachey.