If you are proposing to conduct research and development (R&D) in science, technology, engineering, and mathematics (STEM) education, your work will benefit from effective partnerships with schools and school districts. While almost every education R&D project requires contact with schools, this brief makes the case for partnership. By this we mean a relationship that is long-term, usually involves formal organizational commitments, draws on both partners’ expertise, and has benefits for each partner. As researchers and developers in STEM education, we offer this brief as a summary of what we have learned about creating and maintaining partnerships that support high-quality R&D. The nature of our experience with R&D partnerships has varied, because all of our projects have been different, but we have all found that partnerships enhance learning for researchers and practitioners alike. We also have seen that they work best when approached with realistic expectations and designed for sustainability. This brief describes our observations, emphasizing practical lessons to help other researchers and developers launch and maintain successful partnerships with practitioners.