The National Center on Educational Outcomes (NCEO) held a virtual meeting of an Interim Assessment Advisory Panel on February 16 and 17, 2021, to tap into the panel members' collective knowledge about using interim assessments to support valid interpretations of what students with disabilities know and can do. The panel represented psychometricians, researchers knowledgeable about students with disabilities, state education agency (SEA) assessment and special education leaders, local education agency (LEA) leaders, and parents. The meeting purpose was to develop and disseminate guidance to state departments of education on how to enable all students with disabilities, including students with the most significant cognitive disabilities and English learners with disabilities, to participate in interim assessments in ways that yield valid inferences of what they know and can do. This report summarizes both the overview information provided to meeting participants and the advisors' discussions in the form of takeaways.