To assess the effectiveness of the Trade Adjustment Assistance and North American Free Trade Agreement (NAFTA) Transitional Adjustment Assistance programs, the General Accounting Office (GAO) reviewed available Department of Labor program data and surveyed 20 states representing about 76% of all workers certified under the two programs in fiscal years 1994-1999. The number of workers certified under the programs peaked at about 228,000 in 1999. Program services and benefits payments during the 5 years totaled $1.3 billion. Limited data on program outcomes during and after program participation made it difficult to evaluate the programs' effectiveness. It was recommended that the Trade Adjustment Assistance program be expanded to include secondary workers who supply inputs to firms adversely affected by trade and to workers who lose their job because an employer shifted production to any country outside the Untied States. The following issues affecting delivery of assistance to trade-impacted workers were identified: standardizing worker eligibility rules, placing time limits on training enrollment, and improving program administration. (The following items are appended: characteristics of 1999 program benefit recipients; objectives, scope, and methodology of the GAO assessment; comments from the U.S. Department of Labor; and list of GAO contacts and staff acknowledgments.) (MN)