He began his coaching career as an assistant with Newcastle, working with the U18 and U14 teams in 2006 and 2007. After graduation he returned to the United States in 2009, coaching at
Northwest Christian School in
Phoenix, Arizona for three years, the last as head coach. His first college coaching job was in 2013 for one year as an assistant at Nicholls State University; this was followed by four years at Southwest Baptist University, where he became assistant head coach for the 2017–18 season. In 2018 he joined U.C. Riverside for a few months as an assistant coach. He gave it up to work with his brother Ben full-time to improve his
foul shooting and
jump shot. This was a situation not without controversy. The team had chosen coach John Townsend to work with Simmons. Simmons' choice of his brother has been described as puzzling; the team was reported to be "utterly disappointed" that he decided to go in that direction. He returned
Down Under and to the coaching ranks in early 2020, signing as head coach of the
Franklin Bulls of the
New Zealand NBL.
COVID-19 restrictions led to the 2020 season being suspended and the Bulls subsequently released Simmons to take up a role in the United States. However, he later returned to the Bulls to coach them in the
NBL Showdown Hub season in
Auckland in July 2020. Beginning with the 2020–21 U.S. college season, Simmons has coached the Colorado Christian University basketball team. In his first season as coach, the
D2 Colorado Christian Cougars had a record of 4–14. ==References==