This was a qualitative case study design that used a questionnaire with semi-structured open-ended questions regarding the use of evidence-based strategies in co-taught settings with students who have high-incidence disabilities. The purpose of this study was to determine what strategies were being used by co-teachers in science and social science settings secondary level. A secondary purpose was to determine if those strategies were being used at overall grade levels and in all science and social science co-taught classrooms. During this study, the researcher discovered evidence-based strategies implemented in co-taught settings with students who have high-incidence disabilities. The intent of the study was to improve the achievement of students with high-incidence disabilities in co-taught environments. The review of the literature indicated the need for which evidence-based interventions being supported in the science and social science settings. Lastly, the literature review showed a discrepancy where evidence-based strategies were being used in the science and social science co-taught environments. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]