WASHINGTON, D.C. -- The uninsured rate among U.S. adults declined to 11.9% for the first quarter of 2015 -- down one percentage point from the previous quarter and 5.2 points since the end of 2013, just before the Affordable Care Act went into effect. The uninsured rate is the lowest since Gallup and Healthways began tracking it in 2008.

The percentage of uninsured Americans climbed from the 14% range in early 2008 to over 17% in 2011, and peaked at 18.0% in the third quarter of 2013. The uninsured rate has dropped sharply since the most significant change to the U.S. healthcare system in the Affordable Care Act -- the provision requiring most Americans to carry health insurance -- took effect at the beginning of 2014. An improving economy and a falling unemployment rate may also have accelerated the steep drop in the percentage of uninsured over the past year. However, the uninsured rate is significantly lower than it was in early 2008, before the depths of the economic recession, suggesting that the recent decline is due to more than just an improving economy.

The uninsured rate declined at a slightly slower pace following the second open enrollment period of the federal exchanges compared with the first. The first time around, the uninsured rate fell 1.5 points to 15.6% for the first quarter of 2014 from 17.1% for the fourth quarter of 2013. Comparatively, in that same time frame this year, the uninsured rate fell one point -- from 12.9% to 11.9%.

These results are based on more than 43,500 interviews conducted from Jan. 2 to March 31, 2015, as part of the Gallup-Healthways Well-Being Index. Gallup and Healthways ask 500 U.S. adults each day whether they have health insurance, allowing for precise and ongoing measurement of the percentage of Americans without health insurance. The first-quarter results summarize data captured across both pre-deadline and post-deadline dates, so changes in the uninsured rate over the course of the quarter are not reflected.

Uninsured Rate Drops Most Sharply Among Lower-Income Americans and Hispanics

While the uninsured rate has declined across all key demographic groups since the healthcare law fully took effect in January 2014, it has dropped most among lower-income Americans and Hispanics -- the groups most likely to lack insurance. The uninsured rate among Americans earning less than $36,000 in annual household income dropped 8.7 points since the end of 2013, while the rate among Hispanics fell 8.3 points. The significant drop in uninsured Hispanics is a key accomplishment for the Obama administration, which led targeted efforts to insure this group as they had the highest uninsured population of all key subgroups. However, despite the gains in insurance coverage among Hispanics and lower-income Americans, these groups still have higher uninsured rates than other key subgroups.

Americans aged 26 to 34 have also seen gains in coverage since the healthcare law went into effect -- the uninsured rate among this group is down 7.4 points since the end of 2013, the largest drop among any age group. Blacks have also seen a substantial drop in their uninsured rate since the fourth quarter of 2013 -- 7.3 points.

More Americans Under Age 65 Have Self-Funded Coverage

The uninsured rate among 18- to 64-year-olds dropped to 14.5% in the first quarter of 2015 from 20.8% at the end of 2013, with most of the dip reflecting Americans gaining coverage through self-funded plans, Medicaid and Medicare. Those aged 65 and older are excluded from this analysis of health insurance type because most are covered through Medicare.

The 21.1% of U.S. adults under the age of 65 who say they are covered by a self-funded plan is up 3.5 points since the fourth quarter of 2013. This is likely because more Americans have purchased individual plans through a federal or state health insurance exchange.

The percentage of 18- to 64-year-olds with Medicaid (9.0%) has increased slightly since the requirement for most Americans to carry health coverage took effect. This is not surprising, as many states have expanded Medicaid eligibility so that more lower-income and lower-middle-income Americans can have affordable insurance.

Implications

The percentage of Americans lacking health insurance continued to fall during and after the second open enrollment period that ended on Feb. 15. But the uninsured rate could drop further in the months ahead since the Obama administration established a special enrollment period for March 15 through April 30, aimed at signing up those who realize, while paying their taxes, that they must pay a fine for not obtaining healthcare coverage in 2014.

Some states that run their own exchanges, including Minnesota, Washington and Vermont, also announced special extensions through the end of tax season on April 15. These extended enrollment periods could further drive down the uninsured rate through May, when plans purchased in April go into effect.

Additionally, Medicaid enrollment is not bound by the open enrollment period, which could allow more uninsured to sign up this month -- and throughout the year, if more states choose to expand Medicaid. So far, Arkansas and Kentucky have seen the most improvement in uninsured rates as a result of expanding Medicaid and using state-run marketplaces. Finally, the uninsured rate could vary based on underlying dynamics of the workforce and employment rates in the months ahead.

Survey Methods

Results are based on telephone interviews conducted Jan. 2-March 31, 2015, as part of the Gallup-Healthways Well-Being Index survey, with a random sample of 43,575 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia. For results based on the total sample of national adults, the margin of sampling error is ±1 percentage point at the 95% confidence level.

Each sample of national adults includes a minimum quota of 50% cellphone respondents and 50% landline respondents, with additional minimum quotas by time zone within region. Landline and cellular telephone numbers are selected using random-digit-dial methods.

Learn more about how the Gallup-Healthways Well-Being Index works.