The Census Bureau collects health insurance data using three national surveys: the Current Population Survey's Annual Social and Economic Supplement (CPS ASEC), the American Community Survey (ACS) and the Survey of Income and Program Participation (SIPP). The CPS ASEC collects health insurance data on an annual basis at the national and state level geographies. The ACS collects data on an annual basis for the nation, all 50 states, the District of Columbia, Puerto Rico, every congressional district and all counties, places and metropolitan areas with populations of 65,000 or more. The SIPP collects longitudinal health insurance data at the national level of geography. For more information, visit the About Health Insurance page.
Income, Poverty, and Health Insurance Coverage in the United States: 2011 (P60-243)
National, State and County-Level Uninsured Estimates for the Population at or Below 138% of Poverty: 2009 American Community Survey
Health Insurance Coverage Working Papers: