(16 teams in 2004; 19 teams in 2003)
Eastern Conference
Atlanta Silverbacks, Charleston Battery, Montreal Impact, *Puerto Rico Islanders, Richmond Kickers, Rochester Raging Rhinos, Syracuse Salty Dogs, Toronto Lynx, Virginia Beach Mariners.
Western Conference
Calgary, *Edmonton Aviators, Milwaukee Wave United, Minnesota Thunder, Portland Timbers, Seattle Sounders, Vancouver Whitecaps.
*New in 2004.
Gone: *Charlotte Eagles, Cincinnati Riverhawks, **El Paso Patriots, **Indiana Blast, *Pittsburgh Riverhounds.
*Moved to PSL.
**Moved to PDL.