Compared to men, women are underrepresented in science, technology, engineering, and math (STEM) fields, which contributes to persistent gender inequality in the labor market. In this study, we propose and evaluate a new hypothesis that students’ orientation to accumulate portable skills through educational institutions can help explain gender segregation in fields of study. The results from the first wave of the Survey of High School Students and Mothers in Japan reveal three main findings. First, female students and parents of female students are more likely than male students and their parents to report that it is important to consider the portability of skills when these students choose their future occupations and expect to work in licensed occupations. Second, net of other factors, students with a stronger orientation to skill portability and licensed occupation are significantly more likely to indicate that they are interested in studying occupation-relevant fields (Medicine, Nursing, and Education) than STEM fields. Third, taking the orientation to skill portability and licensed occupation expectations into account significantly reduces the gender gap in intended college major.