In another sign of a precarious era of realignment in college sports, the Big 12 Conference announced invitations Friday to Brigham Young University, Cincinnati, Houston and the University of Central Florida, with the schools able to join as soon as 2023.

The Big 12 had been moving quickly to compensate for the departure of Texas and Oklahoma to the stacked Southeastern Conference, which houses three of the top five football teams (with No. 1 Alabama, No. 2 Georgia and No. 5 Texas A&M). In July, Texas and Oklahoma, two of the Big 12’s founding member schools, announced in a joint statement that they would not renew their existing TV deals beyond 2025, leaving the conference with little choice but to start searching for other candidates to fill the impending hole.

Houston, Central Florida and Cincinnati are currently in the American Athletic Conference, which will dwindle to nine schools after they leave. The A.A.C.’s rules require schools to give a 27-month notice and pay a $10 million buyout before exiting the conference.

Both Houston and B.Y.U. announced that they would join the Big 12 by the 2023-24 season, meaning that the conference could potentially swell to 14 schools if all four invitees join the league before Texas and Oklahoma’s scheduled departure of 2025. But Texas and Oklahoma could leave sooner.

In a statement, B.Y.U. President Kevin J Worthen said joining the Big 12 gives B.Y.U., which is an independent school in football, an “opportunity to reinforce that commitment for student-athletes, allowing them to compete at the highest level both on and off the field.”

Chris Pezman, Houston’s athletic director, in a statement described its move as a “years-in-the-making announcement.”

“Our collective past performances have led us to the opportunity we have today,” Pezman said. “We are humbled, honored, excited and ready to get to work. Together, what we can accomplish is limitless.”

For the Big 12, the maneuver represents yet another bounce-back in recent history. The conference appeared to be on the verge of collapse in the early 2010s when four schools (Nebraska, Missouri, Colorado and Texas A&M) left the conference during another era of N.C.A.A. realignment. That left the Big 12 with only 10 schools. The league managed to survive with an influx of TV money from Fox and when Texas, which had threatened a departure to what was then the Pacific 10, agreed to stay put (until recently).

And just last month, the Pac 12, Big Ten and A.C.C. formed an alliance in response to the bolstering of the SEC as a way to navigate the current era of realignment and create “a collaborative approach surrounding the future evolution of college athletics and scheduling.”

Since then, the Pac 12 has denied any intentions of expansion, and no formal expansion plans have come from the Big Ten or A.C.C., either. After Friday’s development, the monthslong realignment merry-go-round in the Power 5 could slow down.

The A.A.C.’s Commissioner Mike Aresco said in a statement that the realignment news confirms “what we have said all along regarding our status as a power 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 added. “Our conference was targeted for exceeding expectations in a system that wasn’t designed to accommodate our success.”

The universities invited to the Big 12 scheduled news conferences for Friday afternoon.