The ECNL U18/U19 Composite Division is an optional platform for all ECNL member clubs to participate in, should they choose. This division was created alongside the birth year amendment in the 2017-18 Season to accommodate for the quantity of players only eligible to participate in the oldest age group.  The U18/U19 age group is comprised of high school juniors and seniors.

The 2019-20 Season marks the third year of composite competition, seeing growth across conferences and the addition of a post season for the division.