Pursuant to a legislative mandate, GAO reviewed the first-year implementation and enforcement of the Immigration Reform and Control Act of 1986 provisions regarding sanctions against employers who knowingly hire unauthorized workers, focusing on: (1) the Immigration and Naturalization Service's (INS) efforts to educate the public about the law; (2) its planned enforcement approach; and (3) whether the provisions have caused a pattern of discrimination against eligible workers or an unnecessary regulatory burden on employers. GAO found that INS: (1) mailed explanatory handbooks to 7 million employers and began a national media campaign to implement the law and to help ensure voluntary compliance; (2) plans to allocate $60 million during fiscal year (FY) 1988 to implement the employer sanctions provision; and (3) plans to target about 20,000 employers for compliance investigations. GAO also found that the Department of Labor: (1) included investigation of employers' compliance forms in its labor law enforcement efforts; (2) served two employers with notices for knowingly hiring unauthorized aliens; (3) filed 67 alleged violations of the law's anti-discrimination provisions as of September 1987; and (4) filed 52 charges related to employer sanctions with the Equal Employment Opportunity Commission. In addition, GAO found that: (1) the discrimination charges did not constitute a pattern of discrimination or an unreasonable regulatory burden for employers; and (2) data limitations may preclude determination of the existence of a pattern of discrimination or an unnecessary regulatory burden.