Career
Miller rose to prominence in the world swimming scene at the 2014 Short Course World Championships in Doha, Qatar, where he took home a pair of medals, a silver in the men"s 4×100 m medley relay (3:2149) and a bronze in the 4×50 m medley relay (an American-record time of 1:3183). At the 2015 World Aquatics Championships in Kazan, Russia, Miller claimed his first gold medal as part of the United States. team in the 4×100 m medley relay. Swimming the breaststroke leg, Miller recorded a split of 59.23 seconds in the prelims to put the Americans at the top of the final field with a time of 3:31.06.
Miller also competed in the 100 m breaststroke, but failed to advance to the final, finishing in ninth at 59.86 seconds.