Background: The United States faces a shortage of primary care physicians and declining number of medical students choosing primary care careers. Methods: We conducted a secondary analysis of 2 similar national surveys of senior medical students from 1990 and 2007 that addressed student characteristics, specialties chosen, clerkship experiences, perceptions of internal medicine (IM) compared with other specialties, and influential aspects of IM. We compared responses from 1990 and 2007 by analyzing a merged data set of identical items from the 2 surveys (65% of the items). Results: The total sample of 2421 students comprised 1244 at 16 schools in 1990 (response rate, 75%) and 1177 at 11 schools in 2007 (82%). In 2007, there were more women (52% vs 37%, P<.001) and more educational debt (mean, $101 000 vs $63 000, P<.001). Similar proportions of students planned IM careers (23% vs 24%), although plans to practice general IM dropped from 9% to 2% (P<.001). The appeal of primary care as an influence toward IM declined from 57% to 33% (P<.001). More 2007 students reported high satisfaction with the IM clerkship (78% vs 38%, P<.001). Both cohorts thought that workload and stress are greater in IM than in other fields. Students in 2007 felt that opportunities for meaningful work in IM were greater than did students in 1990 (58% vs 42%, P<.001). Conclusions: More students in 2007 than in 1990 viewed IM as a potentially meaningful career. However, the 2007 students had higher debt, more negative perceptions of workload and stress in IM, and less career interest in general IM. To rebuild the generalist physician workforce, improving students' experience of IM in medical school is no longer sufficient. Bolder reform will be required to improve the educational pipeline, practice, and payment of generalist IM physicians.