2009-10: Liam Coughlin skated for the Walpole Express junior team in the Metropolitan Junior Hockey League during his freshman year of high school. He scored 3 goals with 5 assists and 8 penalty minutes.
2010-11: Coughlin transferred to Catholic Memorial and was a bright spot for the traditional Boston high school hockey power as a sophomore on a team that struggled to score. The Knights played one of the tougher schedules in Massachusetts and missed the state playoffs for the first time since 1984 after finishing 8-10-2.
2011-12: Coughlin impressed in the Beantown Classic tournament in the Fall skating for the Greater Boston Junior Bruins before returning to Catholic Memorial for his junior season. In five midget games he scored 3 goals with 1 assist. Serving as a captain for the Knights he scored 5 goals with 5 assists but Catholic Memorial struggled to score goals; missing the Super 8 tournament for the second straight season.
2012-13: Coughlin had a breakout senior season at Catholic Memorial – leading the Knights in scoring with 23 goals and 13 assists during the regular season. Catholic Memorial defeated rival BC High in a three-game first-round series — with Coughlin scoring the game-winner late in the deciding third game — before falling to Malden Catholic 5-2 in the Super Eight semifinals. Coughlin was selected by Dubuque in the second round (30th overall) in the 2013 USHL Entry Draft.
2013-14: Coughlin joined the Vernon Vipers of the British Columbia Hockey League and in October committed to playing college hockey at Massachusetts-Amherst in 2015-16. Coughlin was the third-leading scorer for the Vipers with 18 goals and 27 assists and had a team-high 70 penalty minutes in 53 regular season games. Vernon reached the BCHL finals against Coquitlam after finishing third in the Interior Division. Coughlin scored 7 goals with 6 assists and 14 penalty minutes in 19 playoff games. In April he announced that he was switching his college commitment to Boston University. In his second year of draft eligibility Coughlin was selected by Edmonton in the fifth round (130th overall) in the 2014 NHL Draft.
Coughlin is a project-type prospect at this point but has a big body and is not afraid to get involved in some tough battles, He is an average to above-average puck mover and needs a bit of work in the skating department. Now in his second season in the BCHL after playing high school hockey in Massachusetts, he will have time to develop physically, improve his technical skills and refine his positional game during his college career.
Coughlin is in his second with the Vernon Vipers in 2014-15 and in October 2014 he announced that he was changing his college commitment and will play at the University of Vermont in 2015-16. He was the leading scorer for Vernon as the Vipers finished second to Penticton in the Interior Division. As with most late round, overage draft picks, Coughlin is a work in progress at this point and it is difficult to forecast his NHL potential until he has played at the college level.