Medicaid provides a strong platform on which reform efforts to expand health insurance coverage can be built as two-thirds of the nations uninsured are low-income. Medicaid coverage could be broadened to reach more of the low-income uninsured by eliminating categorical restrictions and establishing a national eligibility standard based on income. This paper analyzes several options for expanding Medicaid using various income eligibility thresholds for adults and children under both current and enhanced participation rates. The analysis shows coverage and cost implications of the options, as well as impacts by region and with payment rates adjusted to promote provider participation.