Miller served as the head coach of the USA men's Under-19 junior national team, which competed at the 2015 FIBA Under-19 World Championship. The USA team ended up with a perfect 7–0 record and a gold medal. As a result of this performance, Miller was named the co-national coach of the year by USA basketball. He was replaced in 2017 by close friend John Calipari as the head coach, ending his 2-year run.