This study explored the impact of developmentally appropriate practices (DAP) on reading test scores as measured by the Mississippi Academics Assessment Program (MAAP) for students in grades 3-5. The research problem is centered on the potential disconnect between traditional teaching methods and the developmental needs of students, which negatively influenced their reading achievement. The study was particularly relevant to educators, policymakers, and students in elementary education who are directly impacted by the effectiveness of instructional practices. The purpose of this qualitative phenomenological study was to examine teachers lived experience of utilizing developmentally appropriate practices in grades 3-5 with the aim of improving MAAP reading test scores. The study employed a qualitative phenomenological methodology to capture the lived experiences of teachers implementing DAP in their classrooms. Participants include elementary school teachers with experiences in teaching reading in grades 3-5 across various leveled schools in the Jackson Public School District. Data was collected through semi-structured interviews, and documented analysis. The research design focused on understanding the subjective lived experiences of these teachers, with data analyzed using thematic coding to identify common patterns and insights. The results showed a positive use of developmentally appropriate practices and improved reading scores on the Mississippi Academic Assessment Program, with teachers' reporting that their experience of implementing developmentally appropriate practices enhance student engagement, comprehension, and critical thinking skills. However, challenges such as time constraints and large class sizes are noted as concerns to full implementation. The study concluded that while DAP can significantly improve reading outcomes, further research is needed to explore practices and strategies for overcoming difficulties with implementation. Recommendations for future research included investigating the long-term effects of developmentally appropriate practices on academic achievement and exploring its impact in diverse educational settings. [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.]