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10.3 Million Poor Uninsured Americans Could Be Eligible for Medicaid if States Opt for ACA Expansion

In June 2012, the Supreme Court ruling on the Affordable Care Act (ACA) put the decision to expand Medicaid coverage to nonelderly adults with incomes below 138 percent of the federal poverty level in the hands of the states. As of January 2014, many states had not used the ACA to expand Medicaid coverage. Nationwide, state decisions about expanding Medicaid affect an estimated 10.2 million uninsured adults with incomes below the poverty level. These poor uninsured adults miss out on Medicaid if their state does not expand the program and are not eligible to receive subsidies for obtaining health insurance coverage through the Marketplaces under the ACA.

The accompanying map provides estimates of the number of poor uninsured adults who would be eligible for Medicaid only if their state expands the program under the ACA. Additional data show the racial and ethnic and age distributions of these individuals in each state. These estimates are derived from Urban Institute analyses of the 2009, 2010, and 2011 American Community Survey that take into account income, immigration status, and other factors that determine eligibility and reflect current Medicaid eligibility requirements for adults.1 States are categorized into two groups: expanding Medicaid under the ACA, and not expanding Medicaid under the ACA as of January 2014. Michigan, which is classified as a Medicaid expansion state, is not enrolling adults in the expansion group until April 1, 2014. This classification of states is based on information on the Centers for Medicare and Medicaid Services (CMS) web site that reflect state decisions and CMS actions as of October 24, 2013.

Based on current information, an estimated 4.4 million poor uninsured adults will become newly eligible for Medicaid in the 25 states and the District of Columbia that have opted to expand Medicaid; an estimated 5.8 million will not be eligible because they live in one of the 25 states that had not committed to expand Medicaid by January 2014. If states make choices that change how they are characterized in this map, we will update it to keep our estimates as current as possible.

1 These estimates are derived using similar methods to those used to produce the estimates released by the Urban Institute in summer 2012, directly after the Supreme Court Ruling on the Affordable Care Act ( and These updated estimates are based on data from the 2009, 2010, and the 2011 American Community Survey that have been aged to 2014 to reflect current conditions. The ACS allows us to estimate reliable local-level estimates, given that the annual ACS sample has over 1.8 million adults nationwide, drawn from each county in the country. The ACA data reflect the most current federal and state-level information available on how income and household units will be defined for determining Medicaid eligibility under both ACA and pre-ACA rules. This analysis builds on the Urban Institute’s ACS Medicaid and CHIP Eligibility Model, which was developed by Victoria Lynch with funding from the Robert Wood Johnson Foundation.

State plans for expanding Medicaid under the ACA


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