[영문]The Patient Protection and Affordable Care Act establishes a national voluntary program for accountable care organizations (ACOs) by January 2012 under the auspices of the Centers for Medicare and Medicaid Services (CMS). The act also creates a Center for Medicare and Medicaid Innovation in the CMS. We propose that the CMS allow flexibility and tiers in ACOs based on their specific circumstances, such as the degree to which they are or are not fully integrated systems. Further, we propose that the CMS assume responsibility for ACO provisions and develop an ordered system for learning how to create and sustain ACOs. Key steps would include setting specific performance goals, developing skills and tools that facilitate change, establishing measurement and accountability mechanisms, and supporting leadership development