The purpose of this study was to determine if teacher certification type impacted student achievement. The researcher hypothesized that students taught by teachers with out-of-field certification will have lower achievement-level scores on Georgia Milestone Assessments than students who are taught by teachers with in-field certification. The null hypothesis held that there is no association between teacher certification type and student achievement levels on Georgia Milestone Assessments. For the purposes of this research, teachers were classified based on certification type—that is, in-field or out-of-field—and students were classified based on the certification type of their teacher and their achievement-level score on Georgia Milestone Assessments. The researcher obtained data from a Georgia school district for school years 2017, 2018, and 2019. The data included in-field and out-of-field teacher lists, teacher schedule files, student schedule files, and Georgia Milestone Assessment results by student. The data were organized and divided into various datasets. The researcher applied the chi-square test to determine the statistical significance of the different datasets. In total, 42 datasets were reviewed and tested using the chi-square test; of these, 35 rejected the null hypothesis, thus showing significant evidence of an association between teacher certification type and student achievement level. Based on the data analyzed in this study, the results suggest that teacher certification type has an impact on student achievement. Limitations of the study include sample size and the inability to encompass other factors that could affect the learning levels. Future research needed includes incorporating the experience level of the teacher and the learning loss related to the COVID pandemic.