High-quality K-12 instructional materials can meaningfully improve teaching practice and student achievement, especially when paired with professional learning support. Yet state policymakers have usually left ultimate authority for textbook selection to school district leaders. Consequently, the quality of materials across U.S. classrooms and within states varies, with potentially detrimental effects on student learning. Yet a growing number of states have been creatively mixing policy, guidance, and supports to promote the use of high-quality instructional materials (HQIM) at the local level. The RAND American Teacher Panel survey data suggests that these strategies are working: adoption of high-quality English language arts and mathematics instructional materials is higher among K-12 schools in those states, as are teachers' reports that they use those materials regularly in their instruction. For states hoping to start or further their instructional material initiatives, this article suggests several key considerations.