On December 20, 2016, CMS announced the formation of a new participation track under the Medicare Shared Savings Program (MSSP) – the Medicare ACO Track 1+ Model – which will start in 2018. Accountable care organizations (ACOs) participating in this model will agree to accept more limited downside risk than ACOs participating in Track 2 or Track 3 of the MSSP, and will be eligible to share up to 50% of savings from care provided to a prospectively assigned beneficiary population. This model will qualify as an Advanced Alternative Payment Model, and enable participating clinicians to become eligible for incentive payments under the new Medicare Access and CHIP Reauthorization Act (MACRA) Quality Payment Program without the higher downside risk mandated under Tracks 2 and 3.