Policy makers are moving rapidly to develop and test reforms aimed at doing a better job of managing the costs and care for people dually eligible for Medicare and Medicaid. This commentary underscores the importance of pursuing new initiatives to address care coordination and spending concerns. It then focuses on key issues raised by proposals that would shift dual-eligible beneficiaries into managed care plans. The paper describes the heterogeneity and complexity of this population, emphasizing the need for approaches closely tied to the needs of particular subgroups of dual-eligible beneficiaries. It warns against moving too quickly, noting the time and resources required to build capacity to serve patients, secure provider networks, and develop an infrastructure for integrating and managing both Medicare and Medicaid services. The commentary cautions that optimistic savings assumptions might not materialize, raises questions about how savings will be allocated, and highlights the need for accountability as new models are being developed and tested to improve care for a population with complex needs.