Hope International University and San Diego Christian College joined the GSAC in the fall of 1999.

Lewis–Clark State College of Lewiston, Idaho joined the GSAC as an affiliate member for men's and women's tennis in 2016.

The departures to the NCAA continued into the 2020s, with Westmont departing for the PacWest in 2023 and Jessup, Menlo, and Vanguard all following in 2024.

To combat this, the GSAC added Benedictine–Mesa, Embry–Riddle at Prescott and Park–Gilbert, to bring membership back to 8 members.

Immediately following these additions, the GSAC announced that it would undergo a rebrand to the Great Southwest Athletic Conference, to reflect its membership now including schools located outside of California.