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.

In recent years, the conference has seen changes with members leaving the GSAC and the NAIA for the NCAA.

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.

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.