Helping English learners and economically disadvantaged students read as well as their more advantaged peers is a struggle for many schools. This study tested a promising program to improve fourth- and fifth-grade students' ability to understand the academic language used in school and support their reading achievement. The supplemental program included reading, speaking, and writing activities for students and training for teachers. About 60 schools were randomly assigned to implement the program for one school year or to continue using their typical strategies. The study compared the average reading performance of the two groups to assess the program's effectiveness.