New York Red Bulls II used to play in USL. As of 2019, the team plays in the USL Championship: the top tier of a re-branded USL pyramid that now also includes USL League One (essentially, USL D2) and USL League Two (formerly, PDL - in essence, a summer amateur league for college players).
There has been some reshuffling of teams around the two professional divisions - USL’s Championship and League One - and a few new clubs have joined the league(s). And there may yet need to be further reshuffling, since CONCACAF is threatening to prevent Ottawa Fury from playing in USL this season.