The Job Corps program has been a central part of federal efforts to provide employment assistance to disadvantaged youths since 1964. The National Job Corps Study, funded by the U.S. Department of Labor (DOL), is designed to provide a thorough and rigorous assessment of the impacts of Job Corps on key participant outcomes. This report describes the implementation of random assignment and sample intake, presents evidence that the process was implemented in a way that will enable the study to realize its goals, and draws lessons from the experience that may be applicable to other program evaluations.