McCarron was selected by the Montreal Canadiens in the first round (No. 25) in the 2013 NHL Draft. He signed a three-year, entry-level contract on July 11, 2013.

McCarron played for USA Hockey's National Team Development Program for two seasons (2011-12, 2012-13) and had five points (three goals, two assists) to help the United States win a silver medal at the 2013 IIHF U18 World Championship, losing 3-2 in the final to Connor McDavid and Canada.

On Jan. 1, 2015, McCarron was acquired by Oshawa of the Ontario Hockey League in a trade with London. He had 27 points (six goals, 21 assists) in 31 games to help Oshawa win the Ontario Hockey League title and the Memorial Cup while being named to the Memorial Cup All-Star Team.

In 2015-16, McCarron had 38 points (17 goals, 31 assists) in 58 games for St. John's of the American Hockey League and was selected for the AHL All-Star Classic. He was called up to the Canadiens and made his NHL debut in a 6-2 loss to the Dallas Stars on Dec. 19, 2015 and scored his first goal in a 4-1 loss to the Calgary Flames on March 20, 2016. McCarron finished the season with two points (one goal, one assist) in 20 games.

He split the 2016-17 season with St. John's and Montreal. McCarron had 19 points (seven goals, 12 assists) in 32 AHL games and five points (one goal, four assists) with the Canadiens. In 2017-18, McCarron had one assist in 18 games with Montreal and spent most of the season with Laval of the AHL, where he had 24 points (seven goals, 17 assists) in 54 games.

NOTES & TRANSACTIONS

• Memorial Cup All-Star Team (2015)
• Traded to Nashville by Montreal for Laurent Dauphin, January 7, 2020.