Nationwide, 9 million individuals are dually eligible for Medicaid and Medicare services and are among the country's most vulnerable. Despite their policy importance, limited work has been done that examines combined Medicaid and Medicare service use and spending patterns for duals. In this brief, we present findings based on analysis of linked 2007 Medicare and Medicaid data, and examine characteristics, health status, utilization, and spending for duals compared to the non-dual Medicare population. We find, among other things, considerable diversity among duals' spending. Results show that being a dual is not synonymous with high-spending, and factors that make duals more expensive than other Medicare beneficiaries are not the same factors that make them expensive relative to other Medicaid beneficiaries. Results suggest that decision-makers should adopt a multi-pronged approach in developing approaches to improve care delivery and efficiency for duals.