This study investigates the relationship between educational loan debt and horizontal education-occupation mismatch, or the extent to which an individual works in an occupation unrelated to their degree field. Research has documented rising levels of debt for all Americans, particularly young adults. While researchers have identified the potential social, economic, and life-course consequences for young Americans burden with large quantities of debt, less is known about the impact of educational loan debt on labor market decisions and outcomes. One particular labor market outcome is horizontal education-occupation mismatch. The purpose of this research is to examine if there is a relationship between an individual’s amount of undergraduate educational loan debt and their likelihood of horizontal mismatch. Furthermore, this study aims to test if the relationship between educational loan debt and horizontal mismatch is moderated by predicted salary. Using a sample of young adults (aged 20 to 34) from the National Survey of College Graduates (survey years 2013, 2015, and 2017), I find that undergraduate educational loan debt does not impact the likelihood of horizontal educational-occupation mismatch, once controlling for basic demographic characteristics and predicted salary. Further testing does reveal that predicted salary is negatively associated with the likelihood of horizontal mismatch; however, the relationship between educational loan debt and horizontal mismatch is not moderated by predicted salary. The findings of this study highlight the important of controlling for predicted salary in the analysis of horizontal education-occupation mismatch.