Students need strong literacy skills to succeed in core academic subjects--English, mathematics, science, and social studies--and to be prepared for college and careers. "Reading Apprenticeship"® is a professional development program that aims to help teachers improve their students' literacy skills. The program also aims to improve student social-emotional learning outcomes such as belonging, social awareness, growth mindset, and self-efficacy. "Reading Apprenticeship"® trains teachers to model reading comprehension strategies and help students practice these strategies in their classrooms. This What Works Clearinghouse (WWC) intervention report summarizes the available evidence on the effects of "Reading Apprenticeship"® on student achievement outcomes in middle and high school. The WWC identified nine studies that investigated the effectiveness of "Reading Apprenticeship"®, with five studies meeting WWC standards. Findings from all five studies meeting WWC standards suggest that "Reading Apprenticeship"® had potentially positive effects on science achievement and grade point average and uncertain effects on achievement in life sciences, social studies, literacy, reading comprehension, vocabulary, and mathematics. [For the Intervention Brief, see ED625921.]