How the BLS defines the different levels of unemployment for the US U-1, persons unemployed 15 weeks or longer, as a percent of the civilian labor force; U-2, job losers and persons who completed temporary jobs, as a percent of the civilian labor force; U-3, total unemployed, as a percent of the civilian labor force (this is the definition used for the official unemployment rate); U-4, total unemployed plus discouraged workers, as a percent of the civilian labor force plus discouraged workers; U-5, total unemployed, plus discouraged workers, plus all other marginally attached workers, as a percent of the civilian labor force plus all marginally attached workers; and U-6, total unemployed, plus all marginally attached workers, plus total employed part time for economic reasons, as a percent of the civilian labor force plus all marginally attached workers.