Since No Child Left Behind was introduced, kindergarten through 12th-grade educators have seen a dramatic increase in accountability, rigor of standards, and responsibilities in the classroom (New America Foundation, 2015). In order to meet the increased demands of federal education regulations in second through fourth grades, many administrators are looking for alternative methods to ensure student success (Gewertz, 2014). Departmentalization is one of the alternative methods being used (Jacobs, 2014). Educators believe departmentalization results in many benefits (Chan & Jarman, 2004); however, historical research has contradicted this view (American Association of School Administrators, 1965). With the demands of today's standards for education, the connection, if any, between student success and departmentalization must be determined. This study was designed to determine if there is a statistically significant difference in student success metrics between students in second through fourth grades in traditional classrooms versus students in departmentalized classrooms. In this study, student success metrics included raw scores on norm-referenced tests, percentile scores on norm-referenced tests, and grade-level averages on norm-referenced tests. These student success metrics are used in Arkansas to determine federal and state funding eligibility (New America Foundation, 2015). The statistical tests used in this study yielded inconsistent results as to a statistical difference between traditional classroom environments and departmentalized classroom environments in second through fourth grades. Factors other than classroom environment, such as teacher training, principal leadership, technology, and parent involvement, may have had an effect on student achievement (Buabeng-Andoh, 2012; Sebastian & Allensworth, 2012). [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/en-US/products/dissertations/individuals.shtml.]