Over the last three decades in the U.S., schools have endeavored to provide more equitable access to rigorous courses, especially for racially or socioeconomically marginalized students, and increased those students' participation in higher level courses. Despite such improvement, the gaps in high level courses enrollment among racially or socioeconomically different student groups still remain with those marginalized students underrepresented in the high level courses. The present study focused on another marginalized group of students, English language learners (ELLs) and sought to identify school practices that may improve ELLs' access to advanced math courses in high school. Using the High School Longitudinal Study of 2009, the present study examined three key school practices in association with ELLs' taking advanced math: i) student choice-based math placement policies, ii) math encouraging programs for underrepresented studentudy found that only math PLCs had a statistically significant association with the probability of taking advanced math courses, net of prior achievement and other student- and school-level factors. The math PLCs examined here represented a collaboration among math teachers to learn effective teaching methods and discuss their teaching/learning belief for students including ELLs or under-performing students. It found no differential effects of school practices and ELLs' taking advanced math courses, the main focus of this study. However, the findings indicate that ELLs can also benefit from high quality math PLCs as much as other students. The key finding of the present study suggests the possible area that school leadership and educators should develop to improve students' access to advanced math courses net of their prior achievement. Particularly for ELLs, the finding suggests that training content area teachers may help ELLs more readily access academicarformance. Most importantly, considering taking advanced math in high school is a critical issue for ELLs in regard to their participation in the STEM (science, technology, engineering, and mathematics) workforce in the future, there should be more research that explicitly investigates school policies and practices that may facilitate ELLs' access to higher level courses in high school. keywords: English language learners, High School Longitudinal Study of 2009, math professional learning communities, student choice, advanaced math