The 2011 Lamar Hunt U.S. Open Cup tournament proper features teams from four of the five tiers of the American Soccer Pyramid. These four levels—Major League Soccer, United Soccer League's Pro League, the USL's Premier Development League, the National Premier Soccer League, and the United States Adult Soccer Association— each have their own separate qualification process to trim their ranks down to their final club delegations in the months leading up to the start of the tournament proper.
The event will feature 40 teams. Eight clubs from Major League Soccer will participate, six that automatically qualify based on last season's league position and two that qualify through a play-in tournament. In addition, 11 USL Pro League clubs, 9 clubs from the USL Premier Development League, 4 clubs from the National Premier Soccer League,[1] and 8 USASA clubs and will also qualify.[2]
The provisional second tier of the soccer pyramid, a reincarnation of the North American Soccer League, was disallowed by the United States Soccer Federation for the American-based clubs to participate into the tournament, mainly due to scheduling conflicts it would cause.[3]