As part of an emerging research agenda on the political impact of remittances in high-migration countries, this article explores the conditions under which organized migrants are likely to engage in transnational public-private partnerships with their home governments through a comparison of Mexico and El Salvador. Both countries have well-organized migrants who have cofinanced community projects back home. But this collaboration has been more sustained, multifaceted, and negotiated in Mexico than in El Salvador. These outcomes are linked to four factors: the density and type of migrant organizations, the territorial distribution of state authority and resources, the extent and nature of diaspora outreach, and legacies of state-society relations. The article discusses how this framework might be applied to other high-migration countries and whether there is room for agency in creating more favorable conditions for migrant-state collaboration.