This special issue on Contested Categories in the Context of Migration takes up Cecilia Menjívar’s call to direct our attention to “the importance of state-created categories and classification systems that determine eligibility for tangible and intangible resources” (Menjívar 2023). International migration is a particularly fruitful site for examining such state-created categories and processes of categorization. On the one hand, states use categories to manage migrants’ entry, reception, and residence, making categorization extremely consequential for individual migrants. On the other hand, bureaucratic documentation and cultural understandings of categories often differ greatly between migrants’ home countries and receiving states. As a result, governments, the public, and actors involved in processes of migration negotiate categories under extremely high stakes and often with unequal and shifting power relations. Migration scholars must thus pay attention to systems of categorization to understand the management of migration and migrants’ own lived experiences, and scholars (from within migration studies and other research fields) interested in categorization should recognize migration as a site where existing categories can be seen with rare clarity, and novel and emerging categories can be identified.