The Affordable Care Act authorizes the Centers for Medicare and Medicaid Services (CMS) to establish a Medicare Shared Savings Program that will allow a new form of health care provider, the accountable care organization, to participate in the Medicare program. On March 31, 2011, CMS released a much anticipated Notice for Proposed Rule-Making, which contains proposed rules for implementing the new program. CMS is soliciting public comment on the proposal, which will be incorporated into the final rule to be published later this year. A summary of the proposal is provided for downloading.