Four schools are set to announce as early as Thursday that they plan to depart the Mountain West to join the Pac-12, sources confirmed to ESPN.

Boise State, Colorado State, San Diego State and Fresno State have applied for Pac-12 membership to begin in the 2026-27 academic year, sources said.

They would join Oregon State and Washington State, the conference's two remaining school following its collapse last summer.

Mountain West bylaws require departing schools to pay an exit fee of roughly $18 million with two years notice, which is what the four schools expect to pay, a source said. (That number would jump to $36 million with one year's notice.)

The Pac-12 is expected to be in position to help the schools with the exit fees, in part, due to withheld media rights distributions fees to departed members and other conference assets. The conference would also be subjected to an additional $43 million in poaching fees, as outlined in the scheduling agreement between the conferences this year that resulted in both OSU and WSU playing six Mountain West opponents.

Once these four additions are confirmed, the conference would still need to add two more to reach the NCAA minimum requirement. The conference is in the first of a two-year grace period afforded by NCAA bylaws to exist below the minimum in the case of departures.

News of the four schools set to join the Pac-12 was first reported by Yahoo Sports.