Hammon was hired by the San Antonio Spurs as an assistant coach in 2014. She became the second female assistant coach and the first female full-time assistant coach in NBA history. Hammon is also the first full-time female assistant coach in any of the four major professional sports in North America. Hammon served as the team's Summer League head coach in 2015; she is the first woman to be a head coach in that league. On December 30, 2020, Hammon became the first female acting head coach in NBA history after Spurs' head coach Gregg Popovich was ejected during a game against the Los Angeles Lakers.