A recent policy statement issued by the U.S. Department of Health and Human Services (HHS) and U.S. Department of Education (DOE) on early childhood inclusion presents extensive recommendations for state and local actions that could improve young children's access to high quality inclusive preschool programs (HHS/DOE, 2015). This brief builds on the research review and policy recommendations in the HHS/DOE policy statement. It highlights research relevant to three questions: (1) What are the effects of inclusive preschool on children's early learning and development?; (2) What is known about the quality of inclusive preschool programs?; and (3) What is known about how to improve the quality of inclusive preschool? In a final section, this brief presents recommendations for policies that are supported by research, including policies related to the funding of early care and education programs, states' professional development systems, and investments in gathering critical information about inclusive preschool programs for ongoing monitoring and quality improvement. The majority of studies reviewed were published between 2000 and 2015 and were found through searches for research articles in the Child Care and Early Education Research Connections collection. Individual studies examining interventions and professional development were included in the review only if they were conducted in inclusive classrooms, while existing reviews sometimes include research in other settings.