Departmentalization has been a part of our educational practice for many years and is becoming a more common practice at the elementary level in the United States. However, it is difficult to support the idea of teaching by subject area when limited data exist to truly demonstrate the effects of departmentalization. Therefore, it is necessary to look at the benefits and challenges of departmentalization to begin to understand how the structure affects student achievement in elementary education. Although this quantitative study, which used a causal-comparative design, did not find statistical significance on overall district and state testing, there was statistical significance at a .05 significance level in math scores.