Differences in health along social, economic and racial or ethnic lines are known as "health disparities" or "social disparities in health." New research presented in this reportand supported by previous studiesindicates that hese differences are keeping America from reaching its potential. They are linked to escalating medical costs in the United States and to Americans' quality of life and our productivity as a nation. The conclusions of this report suggest that reducing America's large and persistent health disparities requires taking a broader, deeper look at how health is shaped across lifetimes and generations. Finding solutions to avoidable differences in health requires looking beyond the medical care system to acknowledge and address the many other factors that also can determine a person's health.