The report, "Employment-Based Health Insurance: 2010," said among employed individuals, employment-based coverage declined from 76 percent in 1997 to 70.2 percent in 2010.
During this time period, the employment-based coverage rate for those not in the labor force declined from 45.4 percent to 38.6 percent and for unemployed individuals declined from 33.5 percent to 30.8 percent, the report said.
During the same period, among employed individuals without coverage the rate increased from 14.7 percent to 18 percent, and the rate for those not in the labor force increased from 12.4 percent to 14.4 percent.
A higher proportion of unemployed individuals were uninsured in 2010 at 46.2 percent than in 2005 at 39.8 percent and 2002 at 43.1 percent, the Census said.
"The report highlights the prevalence of employment-based health coverage among various socio-economic groups including coverage obtained outside the workplace," Hubert Janicki, an economist with the Census Bureau's Health and Disability Statistics Branch, said in a statement.
"Unemployed and individuals not in the labor force with employment-based coverage were generally covered by a previous employer's plan or someone else's, such as a spouse's or a parent's employer."