[영문]To compare the extent with which child-only and family coverage (child and parent insured) ensure health care access and use for low income children in California and discuss the policy implications of extending the State Children's Health Insurance Program (California's Healthy Families) to uninsured parents of child enrollees.We used secondary data from the 2001 California Health Interview Survey (CHIS), a representative telephone survey.We conducted a cross-sectional study of 5,521 public health insurance?eligible children and adolescents and their parents to examine the effects of insurance (family coverage, child-only coverage, and no coverage) on measures of health care access and utilization including emergency room visits and hospitalizations.We linked the CHIS adult, child, and adolescent datasets, including the adolescent insurance supplement.Among the sampled children, 13 percent were uninsured as were 22 percent of their parents. Children without insurance coverage were more likely than children with child-only coverage to lack a usual source of care and to have decreased use of health care. Children with child-only coverage fared worse than those with family coverage on almost every access indicator, but service utilization was comparable.While extending public benefits to parents of children eligible for Healthy Families may not improve child health care utilization beyond the gains that would be obtained by exclusively insuring the children, family coverage would likely improve access to a regular source of care and private sector providers, and reduce perceived discrimination and breaks in coverage. These advantages should be considered by states that are weighing the benefits of expanding health insurance to parents.