In response to Committee requests from the U.S. House of Representatives, the Government Accounting Office examined the extent to which children in Medicaid are receiving Early and Periodic Screening Diagnostic and Treatment (EPSDT) services. State efforts to improve service delivery and federal government efforts to ensure that state Medicaid programs provide covered EPSDT services were also assessed. Information was obtained from state reports to federal agencies, visits to five states with either large numbers of children in managed care or innovative EPSDT programs (California, Connecticut, Florida, New York, and Wisconsin), and reviews of major court orders and legal settlement agreements. Findings suggested that many children are not receiving health screening services. However, the extent to which children in Medicaid are receiving EPSDT services is not fully known, partly because of unreliable and incomplete state reports. The five states were taking actions to improve data compilation and reporting to better monitor services. Although federal requirements regarding the format and specificity of state reports have been a positive step, these steps do not address the difficulties that states face in obtaining information about EPSDT service delivery, especially in managed care settings. Recommendations include that the Centers for Medicare and Medicaid Services (CMS) work with states to develop criteria and a timetable for assessing and improving the reporting and provision of EPSDT services and that CMS develop mechanisms for identifying practices that could be used as models for other states. (Five appendices include profiles of the five states visited, examples of state actions resulting from EPSDT legal settlement agreements, and comments from CMS and the New York Department of Health.) (KB)