This report provides an assessment of NIH's programs for increasing the participation in biomedical science of individuals from underrepresented minority groups. The report examines, using available data and the results of a survey of NIH trainees, the characteristics and outcomes of programs at the undergraduate, graduate, postdoctoral, and junior faculty levels. The report provides recommendations for improving these programs and their administration. It also recommends how NIH can improve the data it collects on trainees in all NIH research training programs so as to enhance training program evaluation.