The biggest decreases in uninsured rates came among Hispanics, African-Americans and low-income people, according to the latest survey, which relied on 44,000 interviews.
And the largest gains in coverage came from individual insurance plans, such as Obamacare exchange-sold plans as well as in Medicaid, the government-run program for the poor, which has expanded eligibility for more adults in many states under the Affordable Care Act. The percent of adults under age 65 covered by job-based insurance remained stable, at 43.4 percent, around the same rate it has been since late 2013.
A report by Gallup noted that while the uninsured rate may continue to drop, particularly after open enrollment in Obamacare insurance plans begins in November, it may only be a slight decline.
"Those who remain uninsured are likely the hardest to engage," Gallup noted.
The survey is the first to be done since the Supreme Court's decision late last month which ruled that subsidies for eligible Obamacare customers could be issued regardless of the state where they lived. If the high court had ruled the other way, people in 34 states would have lost financial assistance, and the uninsured rate would have increased.