While states and postsecondary institutions are searching for ways to increase the postsecondary access and attainment rates of under-represented minority (URM) and low-income students, the retreat from affirmative action policies in many contexts leaves postsecondary institutions with even fewer tools to augment the diversity of their campuses. One alternative approach is percent plans, such as Texas’ Top Ten Percent Plan (TTPP), whereby students who graduate with a GPA in the top ten percent of their high school class receive automatic admission to any public college or university in the state. Although researchers have investigated a number of the policy’s effects, thus far scant research has investigated the magnitude of racial and socioeconomic disparities in college enrollment and the causes of these disparities among students in the top ten percent. This is a significant omission in the literature as research has demonstrated that many high-ability students fail to apply to or enroll in selective institutions, often opting for lower-tier or open-enrollment institutions or choosing not to enroll in postsecondary altogether. The purpose of this study is to investigate factors that contribute to the postsecondary destinations of students who qualified for automatic admission to Texas postsecondary institutions under the TTPP, particularly for URM and low-income students. Our analyses reveal interesting and unexpected patterns of enrollment and significant disparities in the postsecondary destinations of different racial and socioeconomic groups. While certain pre-college factors, such as student interactions with their high school counselor, applying for financial aid, and participation in college preparation programs, explain some of these disparities, these factors are insufficient to fully explain many of the disparities we identified. Implications for educational policy and practice will be discussed.