The availability of sufficient numbers of qualified medical school applicants has been a periodic source of concern. Over the past few years, this concern has emerged again, as fewer men have applied to medical school and as the number of minority applicants has stagnated. This time, however, the cause for concern is greater, because these declining numbers coincide with a growing need for physicians and the possibility that medical school capacity will have to be expanded to avert future physician shortages. Against this background, applications by members of racial and ethnic minorities, who represent an increasing fraction of the college age population, become particularly important. The author reports the trends in education, over several decades, by members of the principal racial-ethnic groups—whites, blacks, Hispanics, and Asians—traces their participation from kindergarten through college, and projects the likelihood of their applying to medical school over the next two decades. (A companion article in this issue reports a parallel study from the standpoint of gender.) One prominent observation is the firm link between academic achievement in the earliest grades and success thereafter. A second is the profound influence of parents’ education, income, and expectations at each step along the way. Inadequacies in either sphere erode the potential for children to reach college and to do so in ways that predict interest in and capacity for medical school. Yet, even when that potential emerges, inadequate finances deflect qualified high school and college students from the paths that lead to medical education. These factors weigh most heavily on black and Hispanic children, particularly boys, but are prevalent among whites, as well. Without aggressive education in the earliest years and without adequate financial support in the later years, it is not clear that there will be a sufficiently large pool of qualified applicants for the number of medical school seats that must exist in the future.