The administrators at the study site were concerned that teachers struggle with differentiated instruction (DI) in their classrooms, which involves strategies to support students' levels. Thus, the purpose of this qualitative case study was to learn what DI strategies teachers used at the study site. The conceptual framework of Tomlinson on the differentiated strategies for content, process, the product according to the students' readiness, interests, and learning environment guided this study. The research question was intended to reveal the DI strategies teachers used to educate students with different ability levels. Nine individual educators were interviewed for this research project with questions compiled from the Teacher Keys Effectiveness System (TKES) Standard 4, and answers from participants were recorded and professionally transcribed. The data were analyzed using direct content analysis, an inductive method with the TKES Standard 4 subsections as a framework for organizing the themes. The findings indicated that 7 of the 9 participants shared a variety of strategies, and none of the 7 voiced concerns or problems with any strategies; however, 3 of the 9 participants discussed the lack of enrichment and accelerated strategies being implementing in classes. Therefore, a project was developed to share several strategies teachers can use to differentiate instruction that may address the concerns regarding enrichment and acceleration. The findings may lead to positive social change through a series of professional development programs that help obtain more content areas correlated strategies to increase student learning. [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.]