An investigation was made of the Immigration Reform and Control Act (IRCA) of 1986, which requires employers to verify employment eligibility of workers and imposes civil and criminal penalties against employers who knowingly hire unauthorized workers. The study reviewed federal agency implementation of irca, reviewed discrimination complaints filed with federal agencies and data from groups representing aliens, and used additional methods to obtain data on IRCA's effects. The other methods included a statistically valid survey of more than 9,400 employers and a hiring audit in which pairs of persons (one a "foreign-sounding, foreign-appearing" Hispanic and one an Anglo with no foreign accent) who matched closely on job qualifications applied for jobs with 360 employers in 2 cities. The study found that the IRCA: (1) has apparently reduced illegal immigration and is not an unnecessary burden on employers; (2) has generally been carried out satisfactorily by the Immigration and Naturalization Service and the Department of Labor; and (3) has not been used as a vehicle to launch frivolous complaints against employers. The study also found that widespread discrimination was a result of the irca: many employers discriminated because the law's verification system does not provide a simple or reliable method to verify job applicants' eligibility to work. The discrimination would be reduced if employers were provided with more education on the law's requirements and a simpler, more reliable verification system. (The document includes 22 tables, 20 figures, and copies of the questionnaires.)