This study quantifies the outflow of human capital associated with migration from Guatemala, El Salvador, and Honduras since 1990. To measure the outflow of skills and human capital and how this has changed over time, the study uses information on Northern Triangle migrants residing in the United States, a group that accounts for over 90 percent of all migrants from the three countries. The results suggest that these migrants are, in general, positively selected into migration. That is, based on their observable characteristics, the individuals would have a higher earnings distribution relative to individuals who do not migrate. The results show a decrease in selectivity between the 10-year cohort of migrants who arrived by 2000 and those who arrived by 2014. This finding may reflect increased access to migration networks by lower-income households and individuals. The data suggest that the loss in human capital associated with a 10-year outflow of adults, as measured by foregone local wages, represented 1.9 percent of gross domestic product in El Salvador, 1.5 percent in Honduras, and 1.0 percent in Guatemala.