This paper addresses three questions: (1) How many unauthorized workers are employed in U.S. agriculture? (2) How many unauthorized farm workers would be eligible for a legalization or guest worker program that required e.g. 60, 90 or 120 days of U.S. farm work during a qualifying 12-month base period? (3)How many guest workers would be admitted under the most likely legalization/guest worker programs; that is, what are likely exit rates from the farm work force for newly legalized workers? The concluding section discusses the implications of alternative scenarios for dealing with immigration and farm workers.