It was certified by the National Labor Relations Board on February 24, 2000, as the World Umpires Association (WUA) as a bargaining agent.

[1] The MLUA, led by longtime negotiating attorney Richie Phillips, was decertified by its member umpires (by a vote of 57 to 35) in February 2000, after Phillips' strategy of mass resignations in September 1999 backfired, with MLB simply accepting many of the resignations and promoting new umpires from the minor leagues.

They were denied membership by the MLUA due to crossing the picket line during the 1979 umpires' strike.

[citation needed] On July 17, 2018, the union rebranded itself as the Major League Baseball Umpires Association.

Legal counsel for the union is Altshuler Berzon, LLP of San Francisco, California.