Learning Forward undertakes periodic updates to the Standards of Learning because educator needs, expertise in the field, and research related to professional learning are continually evolving. In addition, evidence and data are critical to implementing and documenting the results-based professional learning that policy and accountability systems increasingly demand. Most importantly, investments of time and resources must be guided by evidence of what works for educators and students. The 2022 revision of the standards was informed by a range of research and input from educators, with a focus on what that has been learned as a field since the last release of standards in 2011. This paper is a summary of the research base for the Standards for Professional Learning, with a discussion of methods, strengths, and weaknesses. It also outlines a future research agenda focused on more clearly delineating how standards-based professional learning leads to positive changes in teaching and learning and on closing cultural and institutional gaps in the research.