18% of Americans under the age of 65 have no health insurance

Several studies estimate the number of uninsured Americans. According to the U.S. Census Bureau, nearly 46 million Americans, or 18 percent of the population under the age of 65, were without health insurance in 2007, their latest data available. Source: DeNavas-Walt, C.B. Proctor, and J. Smith.  Income, Poverty, and Health Insurance Coverage in the United States: 2008.  U.S. Census Bureau., September 2009.