Lack of health insurance coverage is associated with lack of accessibility to preventive health care services such as mammography screening, clinical breast examination, Papanicolaou smear test, digital rectal examination, proctoscopy examination, and cholesterol screening. State and federal public health agencies must have an understanding of insurance coverage of the population to plan intervention programs aimed at early detection of medical conditions. Using data from the March Supplement of the Current Population Survey for the years 1994, 1995, and 1996, this study examines the sources of health insurance coverage in the U.S. The implications of the findings for public health programs are discussed.