This paper examines the impacts of a migrant regularization program implemented in Peru in 2021. We find that the regularization process positively impacted migrant integration through labor outcomes (access to a written contract and increased income), social outcomes, and access to health services. The results of this study provide evidence of the importance of regularization programs for migrant populations and their impacts on well-being and productive integration in a context of high employment informality and limited public service coverage. The lessons learned are essential not only for developing countries where unexpected migratory flows have made regularization processes common but also for similar south-south movements, where the presence of migrants can pose unique challenges for host societies.