This article examines the changing identification and categorization of Palestinian refugees in order to explore the role of definition in shaping both the UNRWA aid regime and the experience of being a Palestinian refugee. The impact of definition—and the definitions themselves—have not been uniform over time. To consider these qualifications and their impact, this article draws on administrative records from the UNRWA archives from the period of the 1950s and 1960s—a time when the immediacy of displacement was beginning to recede, when the crisis of survival was contained, but when UNRWA was still providing full services (rations included) to a large portion of the registered refugees. The article highlights three effects of definitional practice: exposure to new modes of governance, the introduction of new experiences of loss, and the elaboration of political claims and demand for recognition.