The share of Mainers without health insurance rose from 2012 to 2013, making the state one of just two nationally to record an increase, according to new U.S. Census data.

The data was included in one of three health insurance surveys the federal government released Tuesday.

Maine’s uninsured population rose from 135,000 individuals in 2012 to 147,000 in 2013, an increase of 12,000 people, according to the U.S. Census Bureau’s American Community Survey. Last year, 11.2 percent of Mainers lacked health insurance, up from 10.2 percent in 2012.

Going without coverage puts Mainers’ health at risk and threatens their economic security when high medical bills hit, said Emily Brostek of Consumers for Affordable Health Care, an Augusta-based advocacy group.

“We know that people who don’t have health insurance are more likely to have a number of negative health outcomes … There have been some recent studies that show a higher death rate even, ultimately, for people and communities with high uninsurance rates,” she said.

New Jersey was the only other state to record an increase in its uninsured population, which ticked up by 47,000 people.

While Maine’s uninsured rate increased, it remained lower than rates in many other states. The national average was 14.5 percent, dipping by 0.2 percentage points.

The American Community Survey included a margin of error in Maine of 10,000 people. With a sample of 3 million households, it asks whether families are covered at the time of the survey.

Experts noted that the results reflected little about the impact of the Affordable Care Act, which aims to bring health insurance to millions more Americans. The survey was administered prior to the law’s broad expansion of health insurance coverage through private insurance marketplaces and largely before states began expanding their Medicaid programs under the ACA.

Private health insurance policies available through and state-run insurance marketplaces took effect on Jan. 1 of this year.

While Maine was one of 21 states that opted against expanding Medicaid, the health insurance program for the poor, the effect of that decision on uninsured rates won’t play out until 2014 data is available next year, said Genevieve Kenney, co-director and senior fellow in health policy at the Urban Institute in Washington, D.C.

“I don’t think this is being driven by state decisions with respect to the Medicaid expansion,” she said. “It’s a question of timing.”

But in addition to refusing to expand Medicaid, Maine Gov. Paul LePage and the 125th Maine Legislature, led by Republicans, also tightened eligibility criteria for the program in 2011 and 2012. Those changes prevented many low-income adults from qualifying or keeping their coverage.

Enrollment in the program, known as MaineCare, fell by nearly 15,000 people from December 2012 to December 2013, according to the Kaiser Family Foundation. That could prove a significant factor in Maine’s higher uninsured rate, Kenney said.

Other possible reasons include the economic recession, which may have prompted employers to drop or limit expensive health insurance benefits, she said. Most Mainers get health coverage through their jobs.

The share of Mainers with private health insurance — either accessed through work or purchased on their own — fell 6 percent from 2012 to 2013, according to the state insurance bureau.

Private health insurance also grew more expensive in Maine over many of the last few years, though premium costs for new Affordable Care Act plans are significantly lower.

A separate Census report released Thursday, the Current Population Survey, found that the nation’s uninsured rate was 13.4 percent in 2013, or about 42 million people. That survey asked 10,000 households if they were uninsured for the entire previous year.

Because it reflects the year leading up to the ACA’s coverage expansion, that survey similarly sheds little light on the impact of the law, health policy experts said.

Additionally, the Census announced earlier this year a change to how it asks households about their health insurance coverage in the survey, in order to more accurately gauge coverage. That makes comparing rates from 2012 to 2013 unreliable, but Census officials said the data provides a good baseline of the country’s health insurance landscape prior to the law’s implementation.

The Census numbers came out on the same day as a third federal report, conducted by the U.S. Centers for Disease Control, which marked the first federal survey of the nation’s uninsured rate since the health insurance marketplaces opened to consumers. That survey found the country hit a new low in the number of American adults without coverage. In the first quarter of 2014, 18.4 percent of Americans lacked health insurance, down from 20.4 percent in 2013.

Young adults between 19 and 25 years old showed the biggest drop in uninsured rates, at 20.9 percent in early 2014 from 26.5 percent in 2013. The ACA allows parents to keep children on their insurance plans until age 26.

The survey, which sampled 27,627 people, reflected much of the open enrollment period for health exchange plans, which began in January. But it didn’t account for a late rush of signups for plans that wouldn’t have taken effect until April.

Despite the flood of data released Tuesday, the ACA’s impact on the uninsured hasn’t come into clear focus just yet, according to Brostek.

“I think we’ll see the full picture as we get more time and get more data that covers all of 2014,” she said.

Jackie Farwell

I'm the health editor for the Bangor Daily News, a Bangor native, a UMaine grad, and a weekend crossword warrior. I never get sick of writing about Maine people, geeking out over health care data, and...