Unauthorized immigration status profoundly shapes the social and economic outcomes of migrants in the United States, with wide reaching impacts on wages, work life, physical and mental health, and integration into schools, neighborhoods, and local communities. These effects accumulate across the life course, reverberate across generations, and systematically undermine the social mobility of immigrants and their families, limiting their incorporation into mainstream institutions. While research on these associations is vast, knowledge gaps persist due to enduring methodological and data limitations, as well as an unauthorized population that is growing more diverse in its origins and its range of status protections. We review research on the impacts of immigrant legal status, describe persistent methodological obstacles, and explore new approaches and directions for advancing sociological research.