In the 2011–12 season, Bush began appearing in senior international events, competing at the Finlandia Trophy, Nebelhorn Trophy, and Coupe de Nice. He then competed at the 2012 Russian Championships, and finished 4th with an overall score of 223.30 points. Bush was the first alternate for the 2012 European Championships in Sheffield, England. He won the gold medal at the 2012 Russian Junior Championships. Bush finished 5th at the 2012 World Junior Championships in Minsk, Belarus. Bush placed 10th at the 2012 World Team Trophy in Tokyo, Japan.