Discusses the Medicare Shared Savings Program (MSSP) eligibility, participation requirements, and quality measures relative to Accountable Care Organization (ACO) formation.

Recommendations: Organizations considering participating in the MSSP (Medicare ACO program) should carefully review program eligibility requirements and the beneficiary assignment process. Due to beneficiary assignment based on the greater of allowed Medicare charges, new Medicare ACOs may discover fewer assigned beneficiaries than anticipated. Potential shared savings will be reduced by suboptimal quality Therefore, new Medicare ACOs must provide excellent care in 33 outpatient clinical quality and patient satisfaction measures to a void shared savings reduction.