The 2014 Listening Project Report identified several research and data gaps related to Medicare. The cost of Medicare has been a persistent and high-priority concern for policymakers and researchers alike and emerged early as an area of additional research and data need in the Listening Project interviews. Analysts variously point to new medical technology, population aging, and fragmentation in care delivery as potential drivers of Medicare cost growth. Members of the policy community interviewed as part of AcademyHealth’s Listening Project suggested that understanding these causes could help identify ways to contain spending without diminishing quality of or access to care. This Evidence Roadmap explores the existing resources on this issue. It was produced with the support of the Robert Wood Johnson Foundation.