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The 2013 Lamar Hunt U.S. Open Cup tournament proper features teams from all five tiers of men's soccer of the American soccer pyramid.
For the 2013 tournament, all American-based teams from the top two tiers, Major League Soccer and the North American Soccer League, will earns berths into the third and second round propers of the tournament, respectively.
For the third, fourth and fifth tiers of the pyramid, a series of qualification and state tournaments are held to determine the berths into the tournament. Most states began their qualification in October or November 2012 and will conclude in March 2013. These teams will complete the 64-team field in the U.S. Open Cup.
League
National Premier Soccer League
In addition to the two teams from the West qualifying tournament, the following NPSL teams also qualified:
The Erie Admirals, 2012 Great Lakes Division regular season champions, were expected to join but declined citing a variety of reasons. AFC Cleveland as the division's playoff champion was next in line but also declined. Rather than giving the Open Cup berth to the division's third choice, Detroit City FC, they awarded the berth to the club that had the best overall record among the remaining teams league wide (excluding Western Conference), which was the Brooklyn Italians.
NPSL Western Conference Northern Division qualifying tournament
NPSL Western Conference Southern Division qualifying tournament
All six teams of the 2013 Southern Division competed in the qualifying tournament with FC Santa Clarita and San Diego Flash receiving first round byes.
The USCS qualifying tournament consists of 2 groups with the top two finishers moving on to a single elimination bracket, with the winner qualifying for the 2013 U.S. Open Cup play-in round.
+ The San Ramon SC/Los Gatos Storm semifinal was suspended 1–1 in extra time due to a power failure which caused the lights to go out at the stadium. The match was replayed on April 21.