During the first quarter of 2018, seven Medicare accountable care organizations (ACOs) participating in the Medicare Next Generation ACO model dropped out; some of the ACOs said the reason was a change made to risk adjustment factors for the model. In early January 2018, the Centers for Medicare & Medicaid Services (CMS) announced the new Next Generation ACO participants, and that there were a total of 58 participants. There are now 51 Next Generation ACOs. The seven ACOS and their departure dates are as follows: Accountable Care Coalition of Chesapeake in Houston, Texas exited effective March 30, 2018 . . .