Americans in markets across the country could be looking at double-digit premium hikes under ObamaCare next year, according to a new study that's already fueling election-year finger-pointing.

The Kaiser Family Foundation report found premiums for popular low-cost plans under the health care law are projected to increase an average 11 percent in 2017.

Among the sharpest projected increases are: 26 percent in Portland, Ore.; 21 percent in the District of Columbia; and 16 percent in New York City.

The study focused on the two least-expensive -- and very popular -- "silver" policies. It specifically examined the impact of rising premiums on those whose income exceeds the limit to get government subsidies to defray the cost of mandatory insurance.

The income cutoff for those tax credits is $47,520 for an individual and $97,200 for a family of four.

"Several factors will influence how premiums will change in 2017, and there is reason to believe that increases will be higher than in recent years," the report said.

The findings were based on 14 metro areas across the country.

The Portland, New York and D.C. increases were for ObamaCare’s lowest-cost Silver Premium plan. Costs are projected to decrease in just two metro areas -- Providence, R.I. (13 percent) and Indianapolis (4 percent).

The full picture on 2017 premiums will emerge later this summer as the presidential and congressional elections head into the home stretch. The next ObamaCare signup starts a week before Election Day.

Presumptive Democratic nominee Hillary Clinton wants to build on President Obama’s signature health law while Republican nominee Donald Trump wants to repeal and replace it.

Washington Republicans were quick to point out the projected increases and try to tie them to Democrats seeking re-election in November.

“This latest round of double-digit premium increases for consumers is just further evidence that ObamaCare has failed to make health care affordable for Americans,” Bob Salera, a National Republican Congressional Committee spokesman, said Wednesday.

“House Democrats’ continued support for ObamaCare is a slap in the face to the families who are facing rising costs as a direct result of President Obama’s failed health care law, and voters will hold them accountable in November.”

Democratic Congressional Campaign Committee spokeswoman Meredith Kelly called the NRCC statement “a desperate attempt to distract from what this election will really be about: Donald Trump.”

The administration remains steadfast that proposed rates are not what consumers ultimately will pay, citing an April 12 Department of Health and Human Services report and arguing that the average premium in 2016 for people with tax credits increased just $4, from $102 to $106 a month, despite headlines suggesting double-digit hikes.

“And consumers will benefit from shopping and tax credits again this year,” HHS spokesman Benjamin Wakana told FoxNews.com. "This is just the beginning of the rates process ... proposed rates aren’t what most consumers actually pay."

Wakana also argued “the vast majority” of consumers qualify for tax credits that reduce the cost of coverage below the “sticker price.”

The Kaiser analysis examined the impact before subsidies are calculated, however, and found the changes in the second least-expensive plan were almost identical -- with the same three metro areas having similar projected increases and just Providence and Indianapolis showing projected decreases.

Kaiser said the two plans are significant because they are the most common choices in the marketplaces and the second-lowest is the benchmark used for subsidies.

The cheaper plans typically have higher deductibles, with overall costs ranging from market to market. The study found the monthly premium for a 40-year-old nonsmoker in 2017 in the least-expensive Silver plan will range from $192 in Albuquerque, N.M., to $482 in Burlington, Vt.

Final rates may change if regulators push back on the requests from insurers.

Most workers and their families are covered by employers, but about 12 million people get private coverage through ObamaCare insurance markets. Nearly seven in 10 pick the mid-tier silver plans.

About 2 million marketplace customers, though, make too much to qualify for the subsidies. And an estimated 3 million to 5 million who buy their policies outside of markets such as ObamaCare do not receive financial assistance.

For both the subsidized and the unsubsidized, willingness to switch plans may be crucial in keeping premiums more manageable next year.

“If they stay in their same plan they may see a higher premium increase,” said Cynthia Cox, the analysis’ lead author.

The premium increases follow major insurers reporting significant losses, enrollment lower than hoped for, new customers being sicker than expected and other problems.

Medicare and Medicaid, federal agencies that oversees ObamaCare, said recently that the health insurance markets are still in an early trial-and-error stage which could go on for another couple of years, or well into the next president’s term.

FoxNews.com's Joseph Weber and The Associated Press contributed to this report.