Background/Context: The flow of people, including children, across international borders is a growing trend. While research has emphasized the relationship between parental migration and children's educational outcomes, little is known about how child migration itself influences educational attainment. Purpose: To examine the relationship between Mexico-U.S. child migration and (a) completed years of schooling and (b) likelihood of dropping out of school. Subjects: 33,705 Mexican-born individuals between 7 and 22 years old. Research Design: Secondary data analysis. Data Collection and Analysis: Using data from the Mexican Migration Project (MMP134), pooled OLS and logistic regression models were used to examine the relationship between Mexico-U.S. child migration and (a) completed years of schooling and (b) likelihood of dropping out of school. The sample was split into three groups representing age at first migration (0-6, 7-12, 13-15), allowing for investigation of age-specific incentives and barriers to investment in education. Further descriptive analysis explored what children who drop out of school do instead. Findings: Mexican-born children who first migrate to the United States between the ages of 0 and 6 may have an educational advantage relative to their peers who stay behind, while those who migrate between the ages of 13 and 15 have an educational disadvantage. Specifically, migration in early childhood is related to more years of schooling and increased persistence in school for compulsory school-age children; migration in later childhood is associated with an increased likelihood of dropping out of school. Parental education and household wealth are strong, positive predictors of educational attainment, while being from a community with high migration rates is related to fewer years of schooling and a higher likelihood of dropping out. Of those who drop out, the majority of females are engaged in housework while the majority of males are employed as unskilled workers. Further, migrant students who drop out of school in the United States are more likely to be poor, male, members of large families, and have parents with low levels of education. Conclusions: This study suggests that educational policy regarding migrant students cannot be divorced from the larger, national immigration debate. It also identifies key characteristics of migrant students who drop out of school in the United States, which has implications for practice. Schools and support services can target this vulnerable population and the specific challenges to educational attainment it encounters.