The Centers for Medicare & Medicaid Services will partner with up to six states to test a new accountable care organization model for beneficiaries eligible for both Medicare and Medicaid. CMS is accepting letters of intent from states that wish to work with the agency to design certain state-specific elements of the model, and will give preference to states with low Medicare ACO saturation. States can choose to begin the first annual performance period in 2018, 2019 or 2020; letters of intent for 2018 are due Jan. 20, 2017. Once a state is approved to participate in the model, a request for application will be released to ACOs and health care providers in that state. Participating states and ACOs may share in Medicare savings from the model in their state, and safety-net ACOs can receive pre-payment of Medicare shared savings to support their investment in care coordination infrastructure, CMS said. For more on the Medicare-Medicaid ACO model, see the CMS factsheet.