In January 2016, the Center for Medicare & Medicaid Innovation (CMMI) at the Centers for Medicare &
Medicaid Services (CMS) launched the Next Generation Accountable Care Organization (NGACO)
model. This advanced alternative payment model (AAPM) builds on previous CMS accountable care
organization (ACO) initiatives in the Medicare program. NGACOs comprise groups of practitioners and
institutions that come together to coordinate care for fee-for-service (FFS) Medicare beneficiaries.
NGACOs agree to assume responsibility for the total cost and quality of care delivered to a prospectively
aligned beneficiary population during the performance period. Aligned populations are defined as the set
of patients receiving the plurality of certain primary care services from the ACO’s participating providers.
NGACOs share in savings or pay back losses relative to an aligned population’s spending benchmarks set
by CMS. Three cohorts of NGACOs entered the model in 2016, 2017, and 2018, respectively. The model
runs through December 2020.