This brief describes 10 key themes related to the use of comprehensive, risk-based managed care in the Medicaid program and highlights data and trends related to MCO enrollment, the development of actuarial sound MCO capitation payments, service carve-ins, total state and federal spending on MCOs, MCO parent firms, enrollee access to care, and state and plan activity related to quality, value-based payments, and the social determinants of health. Understanding these trends provides important context for the role MCOs play in the Medicaid program overall as well as during the current COVID-19 public health emergency and related economic downturn.