"May 13 is his last show," a source tells PEOPLE. "He'll take the summer off and GMA can integrate him early before September, and this will give Live! more time to find the co-host. He's totally fine with that. Now he can enjoy his summer."
ABC also confirmed the news with this statement to PEOPLE: "After meeting with the producers of both Live! and Good Morning America, and after speaking with Kelly and Michael, we have decided on a plan that best advantages both shows for the future."
The statement continues, "To that end, Michael's last day on Live! will be on Friday, May 13, which not only gives the show the chance to have a nice send-off for him during the May book, but to also immediately begin the on-air search for a new co-host."
"This plan also allows GMA to start integrating Michael into the show more often this summer before his full-time start in September."
In addition to the details of Strahan's departure date, PEOPLE's source confirmed that ABC executives apologized to Strahan, 44, for putting him in a difficult position, after announcing his departure last week, Ripa called out of work on Wednesday, leading to a tense, weeklong standoff, before she returned to work this morning, joking that the "long national nightmare is over."
"They admitted that they handled it wrong and put him in a terrible position," the source says. "The network decided and the show decided that they wanted more time to find the cohost. He's fine either way."
The source adds that "this is not about feeling awkward with Kelly. He was willing to stay until the fall, but the network is saying this gives them more time to find the co-host. He's a team player. He will do what they ask."
As for Ripa's highly anticipated return, Strahan had not spoken to her beforehand, the source reveals, adding that the two had only texted "cordially" over the weekend after she announced she would return.
"He had no idea how she was going to address it. They didn't talk about it beforehand but he respected that it was her thing to do, however she wanted to do it," says the source.
"The vibe between them is all business. It remained tense," the source reveals. "Nobody knew what was going to happen. Nobody shared with Michael what she was going to do. But he just went there to do his show and be professional."
Strahan knew he would be stepping down early before going on air this morning, the source reveals.
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"He knew he would be wrapping up early, he just didn't know exactly when," says the source, adding that he didn't speak with Ripa, 45, after the show, and discussed the exact timing with the network then.
"He's leaving for another show. He's not losing his job," says the source. "So for him it's fine."
A source close to Ripa calls the parting "amicable."
Live! With Kelly and Michael airs weekdays (check local listings).