Cosmo also plays for the Brampton Excelsiors (MSL)[1] Major Series Lacrosse Senior A Men's league.
In 1998, playing with fellow stars Cam Sedgwick and Kaleb Toth, Cosmo and the Lakers won the Minto Cup.
Since the 2018-19 National Lacrosse League season,[2] Cosmo has served as the goaltending coach for the NLL's Buffalo Bandits,[3] the team with which he ended his playing career.
[5] He continued to succeed as a starter for the Stealth, and was selected as the starting goaltender for the Western Division in both the 2005 and 2006 National Lacrosse League All-Star Game.
[10] Cosmo never reported to the Swarm, and five games into the 2012 season he was traded to the Buffalo Bandits for two first-round draft picks.