PASADENA, CA - NOVEMBER 19: A healthcare reform specialist helps people select insurance plans at the free Affordable Care Act (ACA) Enrollment Fair at Pasadena City College on November 19, 2013 in Pasadena, California. The event, sponsored by the Chamber of Commerce and the Los Angeles Association of Health Underwriters, offers one-on-one sessions with insurance experts certified by Covered California to help people enroll for healthcare coverage under the ACA. (Photo by David McNew/Getty Images) Healthcare exchange website. (credit: David McNew/Getty Images)

WASHINGTON (CBS DC) — The rate of uninsured U.S. adults declined to 11.9 percent for the first quarter of 2015, down more than 5 points from the end of 2013 and hitting Gallup’s record for nearly 90 percent of American adults having health insurance.

The newest Gallup-Healthways Well-Being Index poll showed the uninsured rate among U.S. adults decline to 11.9 percent this year, the lowest since Gallup and Healthways began tracking such data in 2008. The rate is down one point from the previous and 5.2 since 2013, just prior to the Affordable Care Act going into effect.

“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,” according to Gallup.

The uninsured rate dropped at a slightly slower pace for the second enrollment period of the federal health exchanges compared to the first.

Although all demographics groups saw increases in health care coverage, the uninsured rate fell most sharply among lower-income Americans and Hispanics – those 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.

Millennials between ages 26 and 34 have also seen a significant 7.4 percent decrease in their uninsured rate from the end of 2013 – largest drop among any age group. The second-largest decrease was in the 18 to 25 age group. And black Americans saw a similar drop of 7.3 points.

The Gallup results are derived from more than 43,500 daily interviews conducted between Jan. 2 and Mar. 31 of this year.