Adolescents with intellectual and developmental disabilities (IDD) tend to receive inadequate comprehensive sex education (CSE). This problem could be addressed by providing sex education taught by general education health teachers to students with IDD in high school, a cost-effective yet underutilized and under researched service model. This qualitative study sought to determine the types of support health teachers need to effectively teach CSE to adolescents with IDD and to identify any misconceptions they have about the sexuality of individuals with IDD. Nine health teachers from 3 public school districts in Northeastern Pennsylvania were studied using a revised version of the Attitudes to Sexuality Questionnaire - Individuals with an Intellectual Disability (ASQ-ID) and semi-structured interviews. Data was analyzed by cross-case pattern analysis to generate a list of recommendations for local districts on how best to support their existing health teachers in the implementation of formal CSE for young adults with IDD. The three primary supports participants need are: (1) support from special education staff; (2) assistance in developing the curriculum and adapting instruction; and (3) additional training. With these supports, general education health teachers can provide effective CSE to adolescents with IDD so they can be equipped with the relationship and sexuality knowledge and skills necessary to lead safe, fulfilling lives. [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.]