Using longitudinal data for a nationally representative sample of ninth graders in South Korea, we examine socioeconomic differences in the likelihood of making transitions into different types of high school and college with a goal of testing the validity of the Effectively Maintained Inequality (EMI) hypothesis. We find significant socioeconomic disparities in the likelihood of attending an academic high school and a four-year university. However, the predicted probabilities suggest that even disadvantaged students typically choose academic high school relative to vocational high school. Further, although disadvantaged students likely end up with a two-year junior college, those disadvantaged students graduating from an academic high school typically choose a four-year university, after controlling for academic achievement and other variables. We discuss the relevance of EMI for South Korea and broad implications for elsewhere where postsecondary education becomes close to be universal.