CMS has announced a new accountable care organization (ACO) demonstration model called the Next Generation ACO ("NGACO"), which will be implemented through CMS' Center for Medicare and Medicaid Innovation (CMMI). The NGACO model involves significantly higher risk levels than under the current Medicare Shared Savings Program (MSSP) and CMMI's Pioneer ACO program. The program is targeted at ACOs with significant experience in population health management and risk assumption. CMS anticipates approximately 15-20 NGACOs will be approved for the program. Many of the NGACO program details have yet to be disclosed, however, CMS has indicated they will be included in the Model Participation Agreement between CMS and participating ACOs. Some of the key NGACO program features are described here.