A universal feature of education systems is to regulate school entry based on the age of prospective students. Commonly, a specific annual cut-off date is employed to group children into starting cohorts. While this procedure limits the developmental heterogeneity in the classroom, some children are still assigned to enter school up to almost 12 months younger than the oldest student in the same year group. These institutionally assigned differences in school entry age based on month of birth exert a strong impact on educational achievementduring the early stages of schooling. Research has been interested in whether these relative age effects persist over the educational career. In general, studies find a weakening effect on academic achievement of relative age in higher grades but the effect sizes vary considerably between countries. This raises the question which role the institutional setup of an education system plays in closing or preserving the achievement gap based on relative age over time. In this paper, we study the effect of early tracking on the evolution of performance gaps in math, science, and reading between relatively old and young students. Relative age might be particularly prone to beget a considerable risk of track misallocation. The differential learning environments for relatively old and young students during secondary education might preserve the initial performance gap. Using a difference-in-differences approach, our preliminary findings suggest that early tracking countries indeed exhibit the strongest propagation of relative age effects into the later stages of the school career.