After retiring from playing, Elwood went into coaching. He served as assistant coach for Connacht and then as coach of the Ireland under-20 side, where he won a Grand Slam in 2007. In 2010, he became head coach of Connacht and led the team to the Heineken Cup for the first time. He held this position until his decision to resign at the end of the 2012–13 season. He has since taken a variety of roles within the provincial set up, taking the role of Domestic Rugby Manager in 2015. Elwood returned to first team coaching in 2016 when he became kicking coach. In 2017, he moved roles again when he was appointed head of the Connacht Academy.