The diversity of the U.S. population is one of its fundamental strengths as a nation. Over the last several decades, scientific advances have contributed to improving the health and quality of life of many people in the United States. However, low-income populations, underserved rural populations, and racial and ethnic minority populations have not benefited from these advances and have a higher prevalence and incidence than the population as a whole of illness and death due to cancer, cardiovascular disease, stroke, diabetes, HIV/AIDS, infant mortality, and other diseases. As a nation, we must develop strategies and interventions to reduce and ultimately eliminate health disparities among disadvantaged populations.