Medicaid has entered a period of volatile change unprecedented in its 51-year history. With 74 million members nationwide, Medicaid provides health coverage to more than one in four Americans, ensuring access to healthcare not only for children, pregnant women, the elderly and people with disabilities, and also for an increasing number of low-income working adults.

2017 saw repeated attempts to fundamentally restructure the Medicaid program, and although Congress is likely to turn its attention to other priorities in 2018, federal legislative efforts to revamp Medicaid remain in play. Short of congressional action, vigorous efforts by federal officials to use administrative authority to reshape the program are a certainty. And perhaps more than ever before, states will test the limits of their purchasing power and federal flexibility to make changes to their programs—driven by the desire to improve value, reduce the rate of expenditure growth, and shape the program to meet their policy and political objectives. At the boundaries of these federal and state efforts, expect the courts to weigh in.

Given the sheer size of Medicaid—the $565 billion program constitutes 17% of health expenditures nationally—significant changes that we are almost sure to see in 2018 will reverberate in states across the country. These changes will impact millions, including consumers, hospitals, health centers and other providers, health plans, life sciences companies, state governments, and local economies.

Download the 10 Trends to watch in this dynamic environment.