The Illinois Child Welfare Department implemented a statewide health care system to ensure that children in foster care obtain quality health care by providing each child with a medical home. This study demonstrates that the Medical Home model works for children in foster care providing better health outcomes in higher immunization rates. These children used the health care system more effectively and cost-effective as reflected in the higher utilization rates of primary care and well-child visits and lower utilization of emergency room care for children with chronic conditions. (Contains 5 tables.)