On October 3, 2017, the Massachusetts Executive Office of Health and Human Services (EOHHS) announced it had selected two Medicaid managed care organizations (MCOs)—Boston Medical Center Health Plan and Tufts Health Public Plans—that will enroll about 200,000 of the state's 1.9 million Medicaid beneficiaries. The new MCO contracts go live in January 2018 as part of a reform effort authorized in the state's latest 1115 Medicaid waiver, which was approved in December 2016. EOHHS is still modifying aspects of the reform, and September 8, 2017, submitted a waiver amendment, that among other requests, asked . . .