Why are transfer students at an increased risk for disengagement and dropout? Previous research suggests that the loss of school-based social relationships play a role. Data from the National Longitudinal Study of Adolescent Health (Add Health) are used to analyze what predicts student transfer and what effect this has on students' social relationships. Results are based on propensity score matching techniques and are compared with those from a more traditional approach that utilizes regression methods. Findings indicate transfer students report fewer school friends and fail more courses. In addition, transfer students report increased closeness to their teachers after changing schools. Conclusions point to the importance of gatekeepers within institutions, such as teachers, to help individuals rebuild social solidarity after mobility between institutions.