Unlike children in most other economically developed countries, children in the United States are not guaranteed health insurance coverage. Indeed, many U.S. children have no health insurance coverage at all. Their lack of coverage restricts their access to health care services: uninsured children have fewer physician visits per year than children with insurance and are less likely to have a usual source of routine health care. 1 In recognition of the importance of health insurance for children’s access to health care, a number of public programs, the largest of which is the federal-state Medicaid program, have been developed to provide health insurance benefits to poor children and others who would not otherwise have access to health care coverage. Indeed, health insurance coverage for all Americans was a key element of the recent effort to reform health care in the United States. 2 Because of the importance of health insurance coverage, many surveys and reports are devoted to gathering and disseminating statistics on the number and proportion of the U.S. population (including children) who have health insurance of various types. However, the statistics they present can appear contradictory. For example, for 1993, there were three major estimates of the number of uninsured children: the Employee Benefits Research Institute (EBRI) estimated that there were 11.1 million children without insurance; the Census Bureau, 9.5 million; and the Urban Institute, 8.7 million. 3 These different estimates were all based on a single data source, the 1994 Current Population Survey (CPS). This Child Indicators article examines the CPS as a source of data on health insurance coverage, the reasons for the different estimates of the numbers of uninsured children, recent trends in health insurance coverage for children, and the growing importance of the Medicaid program as both a current and a potential source of health insurance for children. This analysis suggests that, even though interpretations of CPS data may seem inconsistent, there are some clear trends in health insurance coverage for children. First, the proportion of children 0 to 10 years old who do not have health insurance has declined slightly over the past five years, while the