This 2012 assessment of the first year of work of the Center for Medicare & Medicaid Innovation (CMMI), which was created by the Patient Protection and Affordable Care Act, finds significant progress on the center’s goal of catalyzing innovation in U.S. health care delivery systems towards the triple aim. The assessment was written by the Urban Institute and funded by the Robert Wood Johnson Foundation. The paper provides a comprehensive review of CMMI’s activities to date, including a survey of the goals envisioned by Congress. The authors address CMMI’s major initiatives, including those that address primary care redesign, bundled payments, accountable care organizations, dual-eligible beneficiaries, and the health care system’s capacity for spreading innovative ideas.