Macropolitical forces and societal culture and attitudes typically predicate the care, education, and training of people with disabilities. Due to the prevailing social model of disability and societal culture, students with intellectual and developmental disabilities (IDDs) in public and private Christian education are the topic of debates regarding inclusion models and effective practices. Many parents of students with disabilities want to provide a faith-based education for their children just as much as families without disabilities. However, studies of Christian schools revealed challenges in providing special education services to students with special needs, especially students with IDDs, including lack of funding and resources, program support, qualified teachers, professional development, and lack of successful Christian school special education models. Unlike public schools, private Christian schools were not required by law to offer special education services or implement Individualized Education Programs. Private Christian schools typically do not receive federal funding for resources or training to support their special needs programs. There was a noted gap in the literature on how Christian schools successfully implement special education programs for students with IDDs. This multiple case study analyzed the school-within-a-school (SWAS) special education approach for educating students with IDDs in two Christian schools. The purpose of the SWAS in the Christian school was to provide a smaller environment for education and social development, inclusion, and transition services that meet the unique intellectual and adaptive behavior needs of students with IDDs. The SWAS approach was examined through the lenses of Bronfenbrenner's (1979) ecosystems theory and Crockett's (2011) special education model to explore the interrelatedness of the ecological systems in leading and administrating special education programs for students with IDDs. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]