The purpose of this collective case study was to understand how special education teachers interpret and navigate the concept of the least restrictive environment (LRE) standard in providing educational support for students with intellectual disabilities and autism. The guiding theories for this study were behaviorism and social cognitive theory. These theories play a vital role in highlighting teacher efficacy skills and learned behavior, which are directly correlated to decision-making. The central research question for this study was: how do special education teachers interpret and navigate the concept of the LRE in providing educational support for students with intellectual disabilities and autism spectrum disorder? This research design was a qualitative collective case study. A collective case study encourages the collection of rich, detailed descriptions of each case with a commonality of special education and working with the federal mandate of the Individuals with Disabilities Education Act (IDEA). The cases in this study were individual special education teachers (N = 10) with experience with special education and determining the LRE for students with intellectual disabilities and Autism. The sample pool was taken from currently employed special education teachers in the Commonwealth of Virginia. The data collection methods included a questionnaire, scenario question, individual interviews, and artifacts. The data were analyzed through triangulation of within and cross-case analysis, resulting in the following key findings, which include barriers from school administrators, dissatisfaction from general education teachers, challenges in navigating special education labels, and the decision-making process of special education teachers, which incorporates participants individual experiences in LRE decisions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]