The percentage and number of uninsured Americans rose in 2006 to 15.8 percent, or 47 million, up from 15.3 percent, or 44.8 million, in 2005.
Similarly, the percentage of children under 18 without health insurance increased to 11.7 percent, from 8.7 percent in 2005.
The percentage of Americans covered by government health insurance programs dropped to 27 percent, from 27.3 in 2005.
The high cost of health insurance has for years been a top concern for American businesses. Hospitals regularly charge employers more for medical services than the rates set by the Centers for Medicare and Medicaid Services as a way to make up for revenue lost by treating people who do not have health insurance.