The “Defining High-Quality Instructional Materials for Mathematics: Centering the Assets and Needs of Multilingual Learner and English Learner Students” resource, developed by the High Quality Instructional Materials Learning Partners Coalition (HQIM-LPC), offers a comprehensive framework for developing and evaluating mathematics instructional materials. Featuring contributions from Californians Together, The Education Trust–West, English Learners Success Forum, Loyola Marymount University Center for Equity for English Learners, the Partnership for Los Angeles Schools, San Joaquin Office of Education, and UnboundEd, this resource aims to advance educational equity, focusing on the needs of multilingual learners (ML) and English Learners (EL). It outlines key elements such as alignment with state standards, support for diverse learners, clear implementation guidance, culturally and linguistically sustaining pedagogy, and robust assessments. This resource guide is essential for educators, policymakers, and curriculum designers committed to creating inclusive and effective mathematics education environments.