Addressing the gender gap in science, technology, engineering, and mathematics (STEM) fields may be an opportunity to promote equity and enhance institutional environments and their performance. We aimed to measure male-dominated undergraduate programs’ change in gender diversity over time, whether it has been converging, and whether it correlates with disciplinary ranking. We considered the number of degrees conferred in 60 disciplines over 19 years at 24 universities representing the top 20 universities of two lists using data from the National Center for Education Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS). We found that the nine most male-dominated disciplines fell within STEM, suggesting continued effort is needed to address the gender gap. Eight of the nine most male-dominated disciplines increased in gender diversity over time, especially between the two most recent time periods, suggesting contemporary policies are often effective. We also found that five out of eight of the most male-dominated disciplines converged over time, which may imply increasing homogeneity in these universities’ gender-diversity policies in some disciplines. Of the nine most male-dominated disciplines, computer science and mechanical engineering had statistically significant results that suggested higher-ranked universities in these disciplines weakly correlated with higher disciplinary gender diversity. The weak correlation between rank and women’s representation suggests that universities with increased resources are better able to create effective initiatives to increase women’s representation in STEM. More broadly, our results suggest these 24 universities’ initiatives have been effective in reducing the STEM gender gap from 2002 to 2021, but room for improvement remains.