This final rule implements provisions of the Affordable Care Act relating to the Medicare Shared Savings Program and Accountable Care Organizations. It establishes regulations around ACO eligibility, governance, quality reporting, beneficiary assignment and care coordination. The rule aims to encourage providers to form ACOs to be accountable for Medicare beneficiaries through care coordination and spending. ACOs that meet quality standards can receive bonus payments if total costs come in below spending benchmarks and share in savings with Medicare.