Developmental education courses have been designed to support underprepared students, as they attempt to bridge the gap in academic knowledge among students who enter postsecondary education underprepared for college-level coursework. The effectiveness of these programs, however, particularly in terms of promoting degree attainment, remains an issue of debate. This study seeks to clarify the impact of developmental courses on students' completion of a baccalaureate degree within 6 years, with a specific focus on the differences between STEM and non-STEM majors. Demographic factors such as gender, race/ethnicity, and family income are explored to see how these characteristics may moderate this relationship. The sample for the study include 10,229 students from a southern state who graduated in the class of 2021. Five logistic models are used in the data analysis, incorporating key demographic and academic variables and also progressively introducing interaction terms to explore moderating effects. The findings indicate that students who are enrolled in developmental courses are significantly less likely to complete their degrees within 6 years compared to those who are not, and the odds ratio of 0.71 suggests that developmental coursework is associated with a smaller likelihood of timely degree completion. Considerations and implications for higher education policy and practice are provided.