The Big 12 presidents and chancellors voted on Friday to accept BYU, Cincinnati, Houston and UCF into the conference.
In a statement, the Big 12 said the four schools were "approved unanimously by the eight continuing members."
The move comes less than two months after Big 12 co-founders Oklahoma and Texas announced they would join the SEC by July 1, 2025, leaving the future of the remaining eight schools in the Big 12 in a precarious position. Big 12 officials moved quickly to make the league whole again, forming a subcommittee that concluded that the most successful football schools in the American Athletic Conference -- Cincinnati, Houston and UCF -- were the top choices, along with independent BYU. The Big 12 was waiting until this week when those schools formally indicated they wanted to join the conference.
BYU will join the league for the 2023-2024 athletic season, with Big 12 commissioner Bob Bowlsby saying the other three programs will join no later than July 1, 2024, but possibly earlier. Bowlsby noted that all four have obligations to their existing leagues -- although BYU is a football-independent school, its other programs participate in the West Coast Conference.
AAC bylaws require schools to give a 27-month notice before they leave and pay a $10 million buyout fee. In that scenario, joining by the 2023 season would be a long shot, but some sources have said it is realistic. An earlier exit -- with a higher buyout -- is always a possibility. AAC commissioner Mike Aresco told ESPN on Friday that the conference will be willing to negotiate a higher exit fee to accommodate earlier departures for the three schools.
If that were to happen, it's possible the league could temporarily expand to as many as 14 teams if those schools join before Oklahoma and Texas leave.
"I certainly wouldn't foreclose on any of the institutions coming in as early as July 1 [in 2023]," Bowlsby said.
Bowlsby also said further expansion remains a possibility for the conference.
"We're always going to be open to new opportunities as they present themselves," Bowlsby said. "We're living in a very fast-changing athletic environment, and we will be at 14 for a while, we will drop back to 12, and as there are targets of opportunity or as there are situations that dictate that we change composition, we'll be prepared to do those things."
By adding the four new schools, Bowlsby said, he believes the Big 12 has fortified itself ahead of the departures of Oklahoma and Texas, as well as the potential expansion of the College Football Playoff.
"It's a relative certainty that we will expand the playoff at some point in time," Bowlsby said. "Whether it'll be a 12-team playoff or whether it'll be an eight-team playoff or whether it'll come in Year 11 [of the television contract] or whether it'll come in Year 13, those things are yet to be determined by the board of managers.
"I think that these are very high-quality football programs that are additive to the Big 12 and have the capability, especially with an array of stronger opponents within the conference, we have an opportunity to demonstrate how we can play at the national level."
Bowlsby was part of the working group that proposed a 12-team model in June, although several major realignment moves have since happened. The CFP board of managers is set to meet in Chicago in late September.
Bowlsby said the Big 12 considered Houston and other candidates back in 2016 but ultimately chose to remain at 10 members, noting that it was disappointing for those at Houston to hear. The planned exits of Oklahoma and Texas made the conference reexamine where it stood.
"With Texas and OU moving to the SEC, it caused a renewed consideration of the options that are available," Bowlsby said. "The more our group became committed to one another and moving forward with the group of eight, the more they began to believe adding additional members made good sense."
Bowlsby was familiar with BYU having been part of the previous vetting process when the conference decided not to expand, which helped this time around.
For BYU, moving to the Big 12 represents the conclusion of a yearslong effort to join a power conference.
"Six years ago, people thought it might have been a failure when we didn't get into the Big 12," BYU athletic director Tom Holmoe said. "But at that point in time, we -- our coaches and our student athletes and administration -- determined that this isn't gonna be a failure. 'This is going to be a launching point.'
"I'd say the last six years has been not a full-court press but it's just been a constant effort with all of us together to try to make it happen."
UCF had been seeking to make the jump to a Power 5 conference and athletic director Terry Mohajir, who was hired in February, said putting the athletics program in position to make a move to a power conference was such a high priority, he started making calls about his second day on the job.
Mohajir presented a long-term strategy for the athletic department to school president Alexander Cartwright two months ago, before news broke that Texas and Oklahoma were leaving for the SEC.
"It just so happened that the gates opened up. And we were there," Mohajir said.
Added Cartwright: "Sometimes you get lucky, but you have to be prepared to get lucky, and we were prepared."
Oklahoma and Texas issued a joint statement in late July saying they intend to remain in the Big 12 through June 30, 2025, when the current Big 12 media rights deal expires, but it's possible the schools could attempt to exit sooner. Each university would have to pay a penalty of at least $75 million to $80 million to break that agreement.
While the ACC, Big Ten and Pac-12 formed an alliance in the wake of the SEC's additions, the Big 12 was not involved, a situation Bowlsby discussed Friday afternoon.
"I've had conversations with [conference commissioners] Kevin Warren and George Kliavkoff and Jim Phillips and I think the reason that we weren't included was probably two-fold," Bowlsby explained. "One was they didn't want to be accused of collusion by having all four conferences seeming to gang up on the SEC. And the other was [the Big 12] were in a state of somewhat disarray. We just had two prominent members leave and it wasn't clear whether or not the Big 12 could commit to being a part of that sort of an alliance. I don't really look at ourselves as being on the outside looking in simply because we don't know what [the alliance] going to be.
With the departures to the Big 12, the depleted AAC is expected to hunt for new members, as it will shrink to eight schools.
The president of one remaining AAC member institution issued a statement to address not being picked to join the Big 12.
"Our understanding is that this latest round of expansion for the Big 12 essentially came down to the size of the institutions and the markets in which they reside," Memphis president David Rudd said in a statement that also described the athletic program as being "disappointed" and "frustrated" with the Tigers not being included.
Aresco, the AAC commissioner, chose to view Friday's news as a validation of the quality of the conference.
"The irony that three of our schools are being asked to take the place of the two marquee schools which are leaving the Big 12 is not lost on us," Aresco said. "Our conference was targeted for exceeding expectations in a system that wasn't designed to accommodate our success.
"All three of these institutions have enjoyed unprecedented success as members of The American, as have our remaining schools."
Although the conference hasn't made any statements about which teams it plans to go after, likely targets for the AAC would include top teams from the Mountain West, such as Boise State; Conference USA, such as UAB; or the Sun Belt.
Sun Belt Conference commissioner Keith Gill issued a statement Friday bolstering his league's position.
"The Sun Belt Conference could not have positioned itself better for this moment as the landscape shifts across conferences," he said. "We have never been stronger. The Sun Belt is the best non-autonomy FBS conference in the country. We were the only non A5 conference with two teams ranked in both preseason polls. We finished last year with two teams ranked in the final CFP and we've led FBS in postseason winning percentage the last five years.
"I spoke to our conference CEOs and ADs earlier today about the current realignment in a few FBS conferences and how it puts us in a more advantageous position for our programs to thrive," Gill said. "Throughout this process, if we identify a school that adds value to the Sun Belt, we'll certainly consider them for membership. We feel very good about the quality of our schools, we take pride in who we are, and will continue to build our programs and our great conference."
ESPN's Kyle Bonagura and Andrea Adelson contributed to this report.