May 5 (Bloomberg) — Obamacare reduced the percentage of adults without health insurance to its lowest point since 2008 even as the law remains unpopular with the public, separate surveys showed.

The share of American adults without health insurance declined to 13.4 percent in April from 15.6 percent in the first quarter of 2014, Gallup said, attributing the reduction to the Patient Protection and Affordable Care Act known as Obamacare. About 8 million Americans signed up for private health plans using the law's new insurance exchanges. The uninsured rate is the lowest in Gallup's survey since the 14.4 percent reported in the second half of 2008.

Obama administration officials often cite the Gallup survey as evidence of the law's effect. The government hasn't produced an estimate of any reduction in the uninsured rate, or said with precision how many people who signed up in 2014 didn't have insurance last year. Despite gains in coverage, the law remains unpopular with a majority of Americans, according to a separate survey released today.