Meeting agricultural policy and statistical goals requires a defi nition of U.S. agriculture’s basic unit, the farm. However, these goals can be at odds with one another. USDA defi nes “farm” very broadly to comprehensively measure agricultural activity. Consequently, most establishments classifi ed as farms in the United States produce very little, while most production occurs on a small number of much larger operations. While desirable for obtaining comprehensive national coverage, measurement and analysis based on the current defi nition can provide misleading characterizations of farms and farm structure in the United States. Additionally, more stringent requirements have been proposed for farms to qualify for Federal agricultural program benefi ts. This analysis outlines the structure of U.S. farms, discusses the current farm defi nition, evaluates several potential criteria that have been proposed to defi ne target farms more precisely, and examines how these criteria affect both statistical coverage and program eligibility.