On September 17, 2015, he was dealt by the New York Islanders to the Toronto Maple Leafs in exchange for Taylor Beck, Matt Finn, Christopher Gibson, Tom Nilsson, and Carter Verhaeghe. On July 1, 2016, he was signed as a free agent by the New York Rangers. He played two seasons with the Rangers before being traded to the Tampa Bay Lightning on February 27, 2018. He finished out his NHL career with the Montreal Canadiens at the end of the 2017-18 season. Grabner first came into the league as an undrafted free agent in 2009, after playing four years with the University of Maine Black Bears. In his rookie season, he scored 14 goals and added 31 assists for 45 points in 82 games. He also had three goals and five assists in 16 playoff games as the Islanders made it to the 2014 Stanley Cup Finals. The following year, he not only led all rookies with nine goals but also ranked second on the team with 37 points. He also helped the Islanders reach the playoffs for the first time since 2008. In seven post-season games, he had one goal and three assists. In 2011-12, he improved upon those numbers with 13 goals and 38 points in 79 games. He also had two goals and four assists in seven post-season matches.