The number of Mexicans leaving the U.S. is now greater than the number coming to the U.S., signaling monumental shifts in U.S.-Mexico relations. This is evoking new questions about bi-national collaboration, particularly regarding the wellbeing of transnational children and youth. Analyzing data from the Mexican Census, we identify basic demographic trends of “returnee” children and youth —those in Mexico after living in the US. Most are US-born with a Mexican-born parent, relatively young, and dispersed across the country, with concentrations in municipalities in northern and central states.