Michael McCarron was rated as a top prospect who fulfilled the expectations to be a first-round selection at the 2013 NHL Entry Draft when he was selected, 25th overall, by the Montreal Canadiens. On July 11, 2013, the team signed him to a three-year entry-level contract.
At the start of his career, McCarron trained with the USA Hockey National Team Development Program from 2011 to 2013, and won a Silver Medal with Team USA at the 2013 IIHF World U18 Championships. When McCarron left the NTDP to join the London Knights, in the Ontario Hockey League, he admitted he didn't realize how difficult the transition would be from playing two seasons in the United States Hockey League to the OHL.