In order to address problems related to the health care of children in foster care, policymakers need detailed information about health status, health care utilization, and Medicaid expenditures. This policy brief summarizes a study examining health care utilization and expenditures paid by Medicaid for children in foster care in California, Florida, and Pennsylvania. Data were obtained from the State Medicaid Research Files for the most recent years available in each state (1994 and 1995 for California and Florida, 1993 and 1994 for Pennsylvania). The study population was made up of children under age 19 with a foster care placement during the year. The 3 comparison groups included children under age 19 who received adoption assistance, Aid to Families with Dependent Children, or Supplemental Security Income benefits because of disability. Among the main findings of the study are the following: (1) children in foster care represent between one and three percent of Medicaid children but between four and eight percent of Medicaid expenditures; (2) most children were enrolled in Medicaid before they entered foster care, but between one-third and one-half lost their Medicaid coverage when they left foster care; (3) children in foster care were more likely than other groups of Medicaid children to have a mental health or substance abuse problem; and (4) health care utilization varied considerably across the three states, with foster children in California less likely to receive health care services than foster children in the other two states. (KB)