A central objective of the Affordable Care Act (ACA) is to reduce the number of Americans without health insurance. Providing the opportunity to purchase private insurance through the new health insurance Marketplaces is one of the major ways in which this goal is to be achieved. The people most likely to enroll in Marketplace-based coveragethose the ACA Marketplaces are specifically designed to helpare nonelderly adults with incomes above the national Medicaid-eligibility cutoff (138 percent of the federal poverty level) who are currently uninsured or are purchasing individual coverage. The new Marketplaces will offer a multitude of choices with differing costs and benefits, although all will include coverage within ACA-defined categories of essential health benefits. This brief focuses on how well the target population understands the concepts they will confront as they make their insurance choices.