The Interstate Box Lacrosse Association (IBLA) was a men's semi-professional box lacrosse league based in the United States. From 2019 to 2021, the IBLA served as an official partner of the National Lacrosse League (NLL), operating as a developmental funnel. The league was founded in 2017 to unite regional semi-professional leagues into a system similar to the Canadian Lacrosse Association structure of men's Senior A and Senior B indoor lacrosse teams. As of 2021 there are 52 total teams playing in 17 regional leagues. The Seneca Marksmen are the most recent IBLA champions, defeating the Grand Rapids Grizzlies in Lakeland, Florida on September 19, 2021.