During the late 2010s, South Korea experienced a significant concentration of highly educated workers, particularly in Seoul. This study analyzes the selection and sorting of internal migrants in Korea during this period, applying the income maximization framework of Grogger and Hanson (2011). Leveraging detailed administrative data on inter-regional migration flows by education level, we find that migration patterns are consistent with the predictions of the income maximization model. Specifically, our results on selection indicate that migrants are positively selected on education when the skill-specific wage differential between destination and origin is large. Furthermore, we find that the relative inflow of highly educated migrants is positively associated with the absolute wage difference between high- and low-skilled workers at the destination. Finally, this sorting of skilled workers is especially pronounced for migration flows toward Seoul, supporting the observed concentration of highly educated individuals in the capital during this period.