Literacy—including writing—is closely tied to student success throughout K–12 education, impacting high school graduation and, ultimately, income after graduation. But students across the United States perform poorly on assessments of writing and, despite the important role writing plays in life and learning, educators report they receive insufficient training on teaching writing, both prior to entering the field and while working. To address this problem, the Regional Educational Laboratory (REL) Pacific supported by the U.S. Department of Education, is developing a Secondary Writing Toolkit to support teachers in implementing evidence-based instructional strategies to improve writing among students in grades 6–8. Abt will rigorously evaluate both the implementation and impact of the Toolkit.