About 35,000 more Mainers have gained coverage by signing up for health benefits through the Affordable Care Act, according to a Gallup poll released Tuesday.

The percentage of Maine’s 1.3 million people who didn’t have health insurance dropped 2.8 percentage points, from 16.1 percent in 2013 – before people could enroll in Affordable Care Act coverage – to 13.3 percent midway through 2014, according to Gallup.

The Gallup-Healthways Well-Being Index poll is the first state-by-state breakdown showing the impact the Affordable Care Act has had on the rate of uninsured residents.

It found an overall drop of 4 percentage points in the rate of uninsured residents for states that expanded their Medicaid programs and built or helped manage the law’s new online insurance markets. For states that took only one of these steps or did neither, the reduction was 2.2 percentage points.

Nationally, the uninsured rate dropped from 17.3 percent of U.S. adults in 2013 to 13.4 percent in the second quarter of 2014, the survey found.

Maine’s percentage decline in its uninsured population ranked 22nd, tied with Montana. Arkansas and Kentucky led the nation, with drops of 10.1 percent in Arkansas and 8.5 percent in Kentucky.

Among the 29 states that refused to expand Medicaid or operate their own health insurance marketplaces, Maine did better than the average 2.2 percent decline in the rolls of the uninsured.

“It’s both a good and bad story here in Maine,” said Mitchell Stein, a Cumberland-based independent health policy analyst. “We did better than a lot of states that did not expand Medicaid, but easily could have had another 3 to 4 percentage point decrease if we had expanded Medicaid.”

The Democratic-controlled Legislature approved Medicaid expansion in 2013 and 2014, but failed to override vetoes by Gov. Paul LePage, who steadfastly opposed the expansion. LePage, like many Republican governors, argued that expansion was not financially sustainable, while Democrats and some moderate Republicans said that leaving 70,000 people without coverage would hurt low-income Mainers.

Stein estimated earlier this year that about 8,000 to 10,000 of those Mainers who would have qualified for Medicaid expansion instead purchased subsidized insurance on the marketplace.

Still, the drop in the uninsured rate shows that Mainers desired the health care coverage, said Emily Brostek, executive director of Consumers for Affordable Health Care, a health policy think tank. Brostek said a robust grass-roots effort to sign up Mainers also made a difference.

“There was a really big effort by so many people to make people aware that they could sign up,” Brostek said.

Maine exceeded the U.S. Department of Health and Human Services enrollment projections by 90 percent, she said.

LePage spokeswoman Adrienne Bennett didn’t respond to a message seeking comment Tuesday night.

The Gallup poll highlighted the stark differences in the uninsured rate by state, with some states, like Minnesota, Delaware and Massachusetts, having less than 10 percent of the population uncovered, while states like Texas and Georgia had more than 20 percent uninsured even after implementation of the Affordable Care Act.

The Gallup-Healthways survey combines the quick turnaround of media polls with extensive outreach usually seen in government research. Pollsters interview 500 people a day, 350 days a year, the Associated Press reported.

The 2013 margin of sampling error for most states is plus or minus 1 to 2 percentage points, but it is as high as plus or minus 3.5 points for states with smaller population sizes, such as Wyoming, North Dakota, South Dakota, Delaware, and Hawaii. For midyear 2014 results, the error range increases to as high as plus or minus 5.0 points for these smallest states.