Good teachers are essential for high-quality educational systems. However, little is known about teachers’ skill formation during college. By combining two standardized tests for Colombian students, one taken at the end of senior year in high school and the other when students are near graduation from college, we test the extent to which students majoring in education relatively improve or deteriorate their skills in quantitative reasoning, native language and foreign language, in comparison with students in other programs. We find that teachers’ skills vis-à-vis those in other majors deteriorate in quantitative reasoning and foreign language, although these skills deteriorate less for those in math-oriented and foreign language-oriented programs, respectively. For native language, we do not find evidence of robust differences in relative learning mobility.