The Uninsured and the ACA: A Primer - Key Facts about Health Insurance and the Uninsured amidst Changes to the Affordable Care Act

For more recent data on trends in coverage and the uninsured population, see our Key Facts About the Uninsured Population.

Executive Summary

In the past, gaps in the public insurance system and lack of access to affordable private coverage left millions without health insurance, and the number of uninsured Americans grew over time, particularly during economic downturns. By 2013, the year before the major coverage provisions of the Affordable Care Act (ACA) went into effect, more than 44 million nonelderly individuals lacked coverage.1

Under the ACA, as of 2014, Medicaid coverage expanded to nearly all adults with incomes at or below 138% of poverty in states that have adopted the expansion, and tax credits are available for people with incomes up to 400% of poverty who purchase coverage through a health insurance marketplace. Millions of people enrolled in ACA coverage, and the uninsured rate dropped to a historic low by 2016. Coverage gains were particularly large among low-income adults in states that expanded Medicaid.

Despite large gains in health coverage, some people continued to lack coverage, and the ACA remained the subject of political debate. Attempts to repeal and replace the ACA stalled in summer 2017, but there have been several changes to implementation of the ACA under the Trump Administration that affect coverage. In 2017, the number of uninsured rose for the first time since implementation of the ACA to 27.4 million.2 Those most at risk of being uninsured include low-income individuals, adults, and people of color. The cost of coverage continues to be the most commonly cited barrier to coverage.3

Health insurance makes a difference in whether and when people get necessary medical care, where they get their care, and ultimately, how healthy they are. Uninsured people are far more likely than those with insurance to postpone health care or forgo it altogether. The consequences can be severe, particularly when preventable conditions or chronic diseases go undetected. While the safety net of public hospitals, community clinics and health centers, and local providers provides a crucial health care source for uninsured people, it does not close the access gap for the uninsured.

For many uninsured people, the costs of health insurance and medical care are weighed against equally essential needs, like housing, food, and transportation to work, and many uninsured adults report financial stress beyond health care.4 When uninsured people use health care, they may be charged for the full cost of that care (versus insurers, who negotiate discounts) and often face difficulty paying medical bills. Providers absorb some of the cost of care for the uninsured, and while uncompensated care funds cover some of those costs, these funds do not fully offset the cost of care for the uninsured.

Under current law, nearly half (45%) of the remaining uninsured are outside the reach of the ACA either because their state did not expand Medicaid, they are subject to immigrant eligibility restrictions, or their income makes them ineligible for financial assistance.5 The remainder are eligible for assistance under the law but may still struggle with affordability and knowledge of options. Ongoing efforts to further alter the ACA or to make receipt of Medicaid more restrictive may further erode coverage gains seen under the ACA. On the other hand, state action to take up the ACA Medicaid expansion could make more people eligible for affordable coverage. The outcome of current debate over health coverage policy in the nation and the states has substantial implications for people’s coverage, access, and overall health and well-being.


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