In early 2020, the AEM Center turned its focus to the start of the education continuum by developing Critical Components for providing accessible materials and technologies for children in early childhood programs. Knowledge development activities focused on understanding the complex early childhood educational system, particularly with respect to programs serving children with disabilities under Part B, Section 619 of IDEA. This synthesis summarizes the knowledge development activities that informed the development of the Critical Components for early childhood, including a literature review, insights gained from a partnership between CAST and the Santa Clara Office of Education, interviews/focus groups with national and state technical assistance providers and a crosswalk between the National AEM Center's existing Quality Indicators and the Indicators of High-Quality Inclusion (ECTA and NCPMI).