With the escalating accountability requirements under No Child Left Behind (NCLB), educators face intensified pressure to increase student achievement. As principals strive to meet the demands of federal and state mandates intended to close the achievement gap, schools often implement various organizational structures to help improve student achievement. Changing how schools and classrooms are organized for instruction as a strategy for school improvement has been one response to this pressure. Elmore, Peterson, and McCarthy (1996) believed that changing the way schools are organized will cause teachers to teach differently; hence students will learn differently, and the overall performance of schools will increase. Many organizational patterns in elementary schools have been controversial issues for decades. One of these issues is the implementation of departmentalized classrooms in the fifth grade. Because many elementary students receive their education in a self-contained classroom from one teacher who is responsible for teaching all academic subjects, the implementation of departmentalization may address the pitfalls of the self-contained organizational setting. In the departmentalized setting, teachers provide instruction in their area of specialization and students experience greater success. Furthermore, departmentalization may help elementary schools respond to state standards while seeking to produce higher achievement among students. Many studies have examined the impact of departmentalization on student achievement with numerous opinions on the issue. The literature, however, is dated and lacks empirical evidence. As very little research explores departmentalization at the elementary level, this case study explored how departmentalization impacted staff, students, and academic achievement at an urban elementary school in Mississippi. The data collection included interviews with teachers, surveys from staff and students, observations of classrooms and planning sessions, and analysis of Mississippi Curriculum Test, II (MCT2) data. The findings of this case study revealed students were exposed to multiple teaching strategies from teachers who were able to use their planning time to create learning activities and assessments for fewer subjects. As departmentalization enhanced the fifth grade teachers’ accountability for the students' academic and behavior performances, the teachers felt pressured into adjusting their lessons to the 90 minutes block schedule.