This mixed-methods study couples large-scale analyses of student course-taking with case study data to explore what blocks the gate to enrollment in and successful completion of secondary math courses for students ever classified as English learners (ever ELs). Initial quantitative findings indicate that half of all students across six California districts, including ever ELs, repeated a math course between 8th and 10th grades, with limited evidence of additional learning during students' second time in the course. Ever EL case study findings indicate that interactions between institutional (course placement policies), classroom (ways of knowing), and individual (student motivation) factors shaped students' math course-taking trajectories, suggesting that opportunity to learn is necessary but not sufficient for educational success.