Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
NEW: Since US doesn't have both South and Midwest, the two remaining teams will be divided into US West and US East (as a reminder, US NE is not in the qualifiers, they're on main stage)
Reference chart to remember your possible eligibility: