The U.S. Census Bureau has released its 2011 health insurance coverage estimates for all states and counties in the U.S., and the report found there are more uninsured working-age adults in the U.S. than uninsured children.

The county-level median uninsured rate for adults, ages 18 to 64, is 21.5 percent, for children the median rate is 7.7 percent. This difference, according to the Census Bureau, can be partially attributed to the Children’s Health Insurance Program (CHIP), which provides health coverage to children whose families have income too high to qualify for Medicaid but are unable to afford private insurance.

In almost all states, males had higher uninsured rates than females. Of the 3,143 U.S. counties, males had a significantly higher uninsured rate in 1,003 of those counties. There were no counties in which the uninsured rate for females was significantly higher than for males.

The lowest county-level uninsured rate is in Norfolk County, Massachusetts at 3.1 percent. Alaska had the highest rate of 46 percent in Aleutians East Borough.

The 2011 Small Area Health Insurance Estimates (SAHIE) program models health insurance coverage by combining survey data with population estimates and administrative records. It can be a useful tool when evaluating the impacts of health care policy changes at the state and county levels.