McCoshen played in 38 games for the Florida Panthers in 2017-18, his first full NHL season, finishing with four points (three goals, one assist), 43 blocked shots and 71 hits.

The defenseman, a native of Anaheim, California, was taken by the Panthers in the second round (No. 31) of the 2013 NHL Draft after three seasons with Waterloo of the United States Hockey League and was named to the 2012-13 USHL First All-Star Team. McCoshen played the next three seasons at Boston College, recording 50 points (17 goals, 33 assists) in 110 games. He also played for the United States at the 2014 and 2015 IIHF World Junior Championships.

McCoshen signed with the Panthers on June 19, 2016, and spent most of the 2016-17 season with Springfield in the American Hockey League, finishing with 16 points (four goals, 12 assists) in 68 games. He made his NHL debut April 6, 2017, getting an assist against the St. Louis Blues.

NOTES & TRANSACTIONS

• USHL First All-Star Team (2013)
• Hockey East Second All-Star Team (2016)
• Traded to Chicago by Florida for Aleksi Saarela, October 23, 2019.
• Signed as a free agent by Minnesota, October 19, 2020.