His father, Joe T. San Agustin (1930-2011), was a longtime Guamanian politician who served as Speaker of the Guam Legislature.
Joe S. San Agustin attended John F. Kennedy High School.
[4] In 2020, San Agustin won reelection, with the third highest number of votes cast, and would serve in the 36th Guam Legislature.
[6] On abortion rights, San Agustin stated that "I am anti-abortion, but I cannot support any measure that does not allow exceptions for victims of rape or incest, or if deemed medically necessary to save a life.".
[1] In 2018, San Agustin co-sponsored legislation to introduce a 20-week abortion ban.