This study explores the value in using the difference between a student's predicted first-year grade point average (FYGPA), based on high school grade point average and SAT scores, and their observed FYGPA, namely, their FYGPA residual, as a tool in identifying those at risk for leaving an institution. Specifically, this study examined whether college students who did not perform as expected (earned higher or lower 1st-year grades) were more likely to leave their institution. Based on a large national sample, hierarchical generalized linear modeling was employed to model the relationship between a student's FYGPA residual and retention in college, taking into account both relevant student and institutional characteristics. Results showed that both under- and overperforming students were more likely to leave after their 2nd-, 3rd-, and 4th-year of college as compared to their academically similar peers who performed as expected. Recommendations for postsecondary institutions to incorporate this information as part of a cost-effective and efficient detection tool to identify students that may be at risk for not completing their degrees and to help improve institutional retention rates are provided.