Under health reform, Medicaid eligibility will be expanded to reach nearly everyone under age 65 with income below 133 percent of the federal poverty level. As a result, millions of uninsured adults, including many with very low income and significant health needs, will become eligible for the program. This brief provides details of the benefit and cost-sharing rules that will govern the coverage available to these newly eligible adults Medicaid beneficiaries, and it identifies key considerations for state policymakers making Medicaid benefit design choices.