The insufficient focus on developing writing instruction in education is a significant problem. Despite the crucial link between writing and reading skills and their impact on academic and life success, there is a notable lack of emphasis on writing in schools. Writing A-Z is a digital-first program that helps teachers establish a writing community, teach the writing process, promote self-regulation, and provide a regular time for students to write for various purposes and audiences. This report presents ESSA Evidence for the research base of Writing A-Z by Learning A-Z for Level 4 or IV, Demonstrates a Rationale, including a logic model and literature review that connects academic research studies to features in the product that support learning outcomes.