Similarly , all of Canada 's MLS teams compete in the Canadian Championship .
In the U.S. , the Lamar Hunt U.S. Open Cup has had MLS participation from the league 's inception ; starting with the 2012 cup , each competition features all American - based MLS sides .
All of Canada 's MLS teams compete in the Canadian Championship .
In the U.S. , the Lamar Hunt U.S. Open Cup has had MLS participation from the league 's inception ; starting with the 2012 cup , each competition features all American - based MLS sides .