Key Facts about the Uninsured Population

Lack of health coverage has been a persistent problem in the U.S. The Affordable Care Act (ACA) sought to address gaps in the health coverage system and led to historic gains in health insurance coverage by extending Medicaid coverage to many low-income individuals and providing Marketplace subsidies for individuals below 400% of poverty. The number of uninsured nonelderly Americans decreased from over 46.5 million in 2010 (the year the ACA was enacted) to just below 27 million in 2016. However, for the second year in a row, the number of uninsured people increased from 2017 to 2018 by nearly 500,000 people. This issue brief describes how coverage has changed in recent years, examines the characteristics of the uninsured population, and summarizes the access and financial implications of not having coverage.

Summary: Key Facts about the Uninsured Population
How many people are uninsured?
For the second year in a row, the number of uninsured increased. In 2018, 27.9 million nonelderly individuals were uninsured, an increase of nearly 500,000 from 2017. Since 2016 when the number of uninsured reached historic lows, the number of people who lack health insurance coverage has grown by 1.2 million. Despite these recent increases, the uninsured rate remains substantially lower than it was in 2010, when the first ACA provisions went into effect and prior to the full implementation of Medicaid expansion and the establishment of Health Insurance Marketplaces. Data show substantial gains in public and private insurance coverage and historic decreases in the number of uninsured people under the ACA, with nearly 20 million gaining coverage.
Who are the uninsured?
Most uninsured people are in low-income families and have at least one worker in the family. Reflecting the more limited availability of public coverage in some states, adults are more likely to be uninsured than children. People of color are at higher risk of being uninsured than non-Hispanic Whites.
Why are people uninsured?
Even under the ACA, many uninsured people cite the high cost of insurance as the main reason they lack coverage. In 2018, 45% of uninsured adults said that they remained uninsured because the cost of coverage was too high. Many people do not have access to coverage through a job, and some people, particularly poor adults in states that did not expand Medicaid, remain ineligible for financial assistance for coverage. Some people who are eligible for financial assistance under the ACA may not know they can get help, while others have income above the cutoff for financial assistance. Additionally, undocumented immigrants are ineligible for Medicaid or Marketplace coverage.
How does not having coverage affect health care access?
People without insurance coverage have worse access to care than people who are insured. One in five uninsured adults in 2018 went without needed medical care due to cost. Studies repeatedly demonstrate that uninsured people are less likely than those with insurance to receive preventive care and services for major health conditions and chronic diseases.

What are the financial implications of being uninsured?
The uninsured often face unaffordable medical bills when they do seek care. In 2018, uninsured nonelderly adults were over twice as likely as their insured counterparts to have had problems paying medical bills in the past 12 months. These bills can quickly translate into medical debt since most of the uninsured have low or moderate incomes and have little, if any, savings.

How many people are uninsured?

As millions of people enrolled in new coverage options under the ACA, the uninsured rate dropped to its lowest level from 2013 to 2016; however, amid efforts to alter the availability and affordability of coverage, the uninsured rate has increased in each of the past two years.

Prior to the ACA, gaps in the public insurance system and lack of access to affordable private coverage left millions without health insurance. Under the ACA, Medicaid coverage has been extended to nearly all adults with incomes at or below 138% of poverty in states that have expanded their programs, and tax credits are available for people who purchase coverage through a health insurance marketplace. As a result, the number of uninsured dropped from more than 46.5 million in 2010 to fewer than 26.7 million in 2016. In 2018, the number of uninsured increased to 27.9 million nonelderly individuals.1

Key Details:
  • Following enactment of the ACA in 2010, when coverage for young adults below age 26 and early Medicaid expansion went into effect, the number of uninsured people and the uninsured rate began to drop. When the major ACA coverage provisions went into effect in 2014, the number of uninsured and uninsured rate dropped dramatically and continued to fall through 2016 when just under 27 million people (10.0% of the nonelderly population) lacked coverage (Figure 1).
  • Starting in 2017 and continuing in 2018, the coverage gains stalled. The number of nonelderly uninsured increased for the second straight year in 2018 (to 27.9 million) and the uninsured rate ticked up to 10.4% (Figure 1). The number of uninsured grew by nearly 500,000 from 2017 and by 1.2 million from 2016. The uninsured rate rose by 0.4 percentage points in 2018 from the historic low of 10.0% in 2016. Despite these increases, the uninsured rate remains significantly below pre-ACA levels.

Figure 1: Number of Uninsured and Uninsured Rate among the Nonelderly Population, 2008-2018

  • Administrative data show recent coverage declines in both Medicaid and the Marketplaces. Medicaid enrollment declined by over 2 million people, or 3.1%, from December 2016 to December 2018.2 Enrollment in the Marketplaces also dropped over 900,000 from 12.7 million during the 2016 open enrollment period to 11.8 million during the 2018 open enrollment period.3
  • Continuing trends from the prior year, changes in insurance coverage from 2017 to 2018 showed mixed patterns across groups. While the uninsured rate for poor individuals held steady from 2017 to 2018, the uninsured rate for near-poor nonelderly individuals and those with incomes above 200% of poverty increased significantly (Figure 2). Among people of color, Blacks experienced the largest increase in the uninsured rate by 0.33 percentage points (to 11.5%) in 2018, while the rate for Asians dropped slightly by 0.33 percentages points (to 6.8%), and the rate for Hispanics and Native Hawaiians and Other Pacific Islanders did not significantly change (Figure 2). The number of uninsured children grew by over 100,000 from 2017 to 2018 and the uninsured rate for children ticked up nearly 0.2 percentage points from just under 5.0% in 2017 to 5.1% in 2018. Though these percentage point changes are small, they translate to a large number of people who lost coverage.

Figure 2: Change in Uninsured Rate among the Nonelderly Population by Selected Characteristics, 2017-2018

  • Similar to changes in 2017, the uninsured rate in the group of states that expanded Medicaid was essentially flat overall, increasing by less than 0.1 percentage points, although changes varied by state (Appendix Table A). In contrast, the uninsured rate in states that did not expand Medicaid increased significantly overall (rising by 0.3 percentage points).

Who are the uninsured?

Most people who are uninsured are nonelderly adults, in working families, and in families with low incomes.4 Reflecting geographic variation in income and the availability of public coverage, people who live in the South or West are more likely to be uninsured. Most who are uninsured have been without coverage for long periods of time. (See Appendix Table B for detailed data on characteristics of the uninsured population).

 Key Details:
  • In 2018, over seven in ten of the uninsured (72%) had at least one full-time worker in their family and an additional 11% had a part-time worker in their family (Figure 3).
  • Individuals with income below 200% of the Federal Poverty Level (FPL)5 are at the highest risk of being uninsured. In total, more than eight in ten of the uninsured were in families with incomes below 400% of poverty in 2018 (Figure 3).

Figure 3: Characteristics of the Nonelderly Uninsured, 2018

  • Most (86%) of the uninsured are nonelderly adults.6 The uninsured rate among children was just 5% in 2018, less than half the rate among nonelderly adults (13%), largely due to broader availability of Medicaid/CHIP for children than for adults (Figure 4).
  • While a plurality (41%) of the uninsured are non-Hispanic Whites, in general, people of color are at higher risk of being uninsured than Whites. People of color make up 43% of the nonelderly U.S. population7 but account for over half of the total nonelderly uninsured population (Figure 4). Hispanics and Blacks have significantly higher uninsured rates (19% and 11%, respectively) than Whites (8%) (Figure 4). However, Asians have the lowest uninsured rate at 7%.

Figure 4: Uninsured Rates among the Nonelderly Population by Selected Characteristics, 2018

  • Most of the uninsured (76%) are U.S. citizens and 24% are non-citizens.8 Uninsured non-citizens include both lawfully present and undocumented immigrants. Undocumented immigrants are ineligible for federally funded health coverage, but legal immigrants can qualify for subsidies in the Marketplaces and those who have been in the country for more than five years are eligible for Medicaid.9
  • Uninsured rates vary by state and by region; individuals living in non-expansion states are more likely to be uninsured (Figure 4). Thirteen of the 21 states with the highest uninsured rates in 2018 were non-expansion states as of that year (Figure 5 and Appendix A). Economic conditions, availability of employer-sponsored coverage, and demographics are other factors contributing to variation in uninsured rates across states.

Figure 5: Uninsured Rates among the Nonelderly by State, 2018

  • Nearly three-fourths (74%) of the nonelderly adults uninsured in 2018 have been without coverage for more than a year.10 People who have been without coverage for long periods may be particularly hard to reach in outreach and enrollment efforts.

Why are people uninsured?

Most of the nonelderly in the U.S. obtain health insurance through an employer, but not all workers are offered employer-sponsored coverage or, if offered, can afford their share of the premiums. Medicaid covers many low-income individuals and financial assistance for Marketplace coverage is available for many moderate-income people. However, Medicaid eligibility for adults remain limited in some states and few people can afford to purchase coverage without financial assistance. Some people who are eligible for coverage under the ACA may not know they can get help and others may still find the cost of coverage prohibitive.

Key Details:
  • Cost still poses a major barrier to coverage for the uninsured. In 2018, 45% of uninsured nonelderly adults said they were uninsured because the cost is too high, making it the most common reason cited for being uninsured (Figure 6).
  • Access to health coverage changes as a person’s situation changes. In 2018, 21% of uninsured nonelderly adults said they were uninsured because the person who carried the health coverage in their family lost their job or changed employers (Figure 6). More than one in ten were uninsured because they lost Medicaid due to a new job/increase in income or the plan stopping after pregnancy (13%) and one in ten were uninsured because of a marital status change, the death of a spouse or parent, or loss of eligibility due to age or leaving school.11

Figure 6: Reasons for Being Uninsured among Uninsured Nonelderly Adults, 2018

  • As indicated above, not all workers have access to coverage through their job. In 2018, 70% of nonelderly uninsured workers worked for an employer that did not offer them health benefits.12 Among uninsured workers who were offered coverage by their employer, but did not take up the offer, nine out of ten reported cost as the main reason for declining in 2017 (90%).13 From 2009 to 2019, total premiums for family coverage increased by 54%, and the worker’s share increased by 71%, outpacing wage growth.14 Low-income families with employer-based coverage spend a significantly higher share of their income toward premiums and out-of-pocket medical expenses compared to those with income above 200% FPL.15
  • Medicaid and CHIP are available for low-income children, but eligibility for adults is more limited. As of November 2019, 37 states including DC adopted Medicaid expansion eligibility for adults under the ACA, although only 32 states had implemented the expansion in 2018.16 In states that have not expanded Medicaid, eligibility for adults remains limited, with median eligibility level for parents at just 40% of poverty and adults without dependent children ineligible in most cases.17 Millions of poor uninsured adults fall in a “coverage gap” because they earn too much to qualify for Medicaid but not enough to qualify for Marketplace premium tax credits.18
  • Undocumented immigrants are ineligible for Medicaid or Marketplace coverage.19 While lawfully-present immigrants under 400% of poverty are eligible for Marketplace tax credits, only those who have passed a five-year waiting period after receiving qualified immigration status can qualify for Medicaid.
  • Though financial assistance is available to many of the remaining uninsured under the ACA, not everyone who is uninsured is eligible for free or subsidized coverage. More than half (15.9 million, or 57%) of the uninsured in 2018 were eligible for financial assistance either through Medicaid or through subsidized marketplace coverage (Figure 7). However, over four in ten uninsured (12.0 million) are outside the reach of the ACA because their state did not expand Medicaid, their income is too high to qualify for marketplace subsidies, or due to immigration status. Large increases in premiums in the individual market in 2017 and 2018 made that coverage much less affordable and led to declines in coverage among those who did not receive subsidies.20,21 In addition, some uninsured who are eligible for help may not be aware of coverage options or may face barriers to enrollment.22 Outreach and enrollment assistance was key to facilitating both initial and ongoing enrollment in ACA coverage, but these efforts face challenges due to funding cuts and high demand.23,24

Figure 7: Eligibility for ACA Coverage among Nonelderly Uninsured, 2018

How does not having coverage affect health care access?

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 adults 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.

Key Details:
  • Studies repeatedly demonstrate that the uninsured are less likely than those with insurance to receive preventive care and services for major health conditions and chronic diseases.25, 26, 27, 28 One in five (21%) nonelderly adults without coverage said that they went without needed care in the past year because of cost compared to 4% of adults with private coverage and 7% of adults with public coverage. Part of the reason for poor access among the uninsured is that many (52%) do not have a regular place to go when they are sick or need medical advice (Figure 8).

Figure 8: Barriers to Health Care among Nonelderly Adults by Insurance Status, 2018

  • Many uninsured people do not obtain the treatments their health care providers recommend for them because of the cost of care. In 2018, uninsured nonelderly adults were more than three times as likely as adults with private coverage to say that they postponed or did not get a needed prescription drug due to cost (19% vs. 6%).29 And while insured and uninsured people who are injured or newly diagnosed with a chronic condition receive similar plans for follow-up care, people without health coverage are less likely than those with coverage to obtain all the recommended services.30, 31
  • Because people without health coverage are less likely than those with insurance to have regular outpatient care, they are more likely to be hospitalized for avoidable health problems and to experience declines in their overall health. When they are hospitalized, uninsured people receive fewer diagnostic and therapeutic services and also have higher mortality rates than those with insurance.32,33,34,35,36
  • Research demonstrates that gaining health insurance improves access to health care considerably and diminishes the adverse effects of having been uninsured. A comprehensive review of research on the effects of the ACA Medicaid expansion finds that expansion led to positive effects on access to care, utilization of services, the affordability of care, and financial security among the low-income population.37 Medicaid expansion is associated with increased early-stage diagnosis rates for cancer, lower rates of cardiovascular mortality, and increased odds of tobacco cessation.38,39,40
  • Public hospitals, community clinics and health centers, and local providers that serve disadvantaged communities provide a crucial health care safety net for uninsured people. However, safety net providers have limited resources and service capacity, and not all uninsured people have geographic access to a safety net provider.41,42,43 High uninsured rates also contribute to rural hospital closures, leaving individuals living in rural areas at an even greater disadvantage to accessing care.44

What are the financial implications of being uninsured?

The uninsured often face unaffordable medical bills when they do seek care. These bills can quickly translate into medical debt since most of the uninsured have low or moderate incomes and have little, if any, savings.45,46

Key Details:
  • Those without insurance for an entire calendar year pay for more than one-third of their care out-of-pocket.47 In addition, hospitals frequently charge uninsured patients much higher rates than those paid by private health insurers and public programs.48,49,50
  • Medical bills can put great strain on the uninsured and threaten their financial well-being. In 2018, nonelderly uninsured adults were over twice as likely as those with private insurance to have problems paying medical bills (27% vs. 12%; Figure 9) with nearly two thirds of uninsured who had medical bill problems unable to pay their medical bills at all (64%, data not shown).51 Uninsured adults are also more likely to face negative consequences due to medical bills, such as using up savings, having difficulty paying for necessities, borrowing money, or having medical bills sent to collection.52
  • Uninsured nonelderly adults are also much more likely than their insured counterparts to lack confidence in their ability to afford usual medical costs and major medical expenses or emergencies. Uninsured nonelderly adults are over twice as likely as privately insured adults to worry about being able to pay costs for normal health care (59% vs. 22%; Figure 9). Furthermore, three quarters of uninsured nonelderly adults say they are very or somewhat worried about paying medical bills if they get sick or have an accident, compared to 47% of adults with Medicaid/other public insurance and 43% of privately insured adults.
  • Lacking insurance coverage puts people at risk of medical debt. In 2018, three in ten uninsured nonelderly adults said they were paying off at least one medical bill over time (Figure 9). Nearly one in five consumers (18%) have medical debt in collections, with a median debt of $681.53 More than half (43%) of uninsured people said they had problems paying household medical bills in the past year and are more likely to have medical debt than people with insurance.54,55

Figure 9: Problems Paying Medical Bills by Insurance Status, 2018

  • Though the uninsured are typically billed for medical services they use, when they cannot pay these bills, the costs may become bad debt or uncompensated care for providers. State, federal, and private funds defray some but not all of these costs. With the expansion of coverage under the ACA, providers are seeing reductions in uncompensated care costs, particularly in states that expanded Medicaid.56
  • Research suggests that gaining health coverage improves the affordability of care and financial security among the low-income population. Multiple studies of the ACA have found larger declines in trouble paying medical bills in expansion states relative to non-expansion states. A separate study found that, among those residing in areas with high shares of low-income, uninsured individuals, Medicaid expansion significantly reduced the number of unpaid bills and the amount of debt sent to third-party collection agencies.57


Millions of people gained coverage under the ACA, but recent trends in insurance coverage indicate that coverage gains are eroding. In 2018, 27.9 million people lacked health coverage, an increase of 1.2 million from 2016. Increases in the uninsured threaten the improvements in access to care and overall health and well-being following the ACA. Going without coverage can have serious health consequences for the uninsured because they receive less preventive care; and delayed care often results in serious illness or other health problems. The financial consequences of not having insurance can also be severe, leading to difficulties paying medical bills and higher rates of medical debt among the uninsured. A variety of proposals to expand coverage options and lower costs are currently being debated. They range from proposals that build on the ACA—expanding Medicaid in states that have not yet done so, enhancing and extending marketplace subsidies to more people, and offering a public plan option alongside private insurance in the marketplaces—to proposals to adopt a single Medicare-for-all program that would replace existing forms of coverage. The outcome of this ongoing debate has substantial implications for the individuals and families who face the health and financial consequences of not having health insurance.


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