The Affordable Care Act (ACA) creates new coverage options through Medicaid and new health insurance exchange marketplaces that, taken together, provide assistance to individuals with family incomes up to 400% of the federal poverty level (FPL). The ACA calls for the expansion of Medicaid eligibility to 138% FPL ($15,856 for an individual or $26,951 for a family of three in 2013) in 2014, which would make millions of adults newly eligible for the program. However, this expansion was effectively made a state option by the Supreme Court. If a state does not expand Medicaid, low-income uninsured adults in that state will not gain that new coverage option and will likely remain uninsured. This brief provides an overview of current Medicaid and CHIP eligibility levels for non-disabled children and adults to provide better insight into the impact of the Medicaid expansion.