Roughly 41 percent of counties in the United States could have only one insurer participating on the Affordable Care Act exchanges next year, according to a new analysis from Avalere Health.

This percentage is up from the lack of participation in 2017, when roughly one-third of counties, or 33 percent, had only one insurer participating on the exchanges.

According to their count, there will be 47 counties that will have no insurer participating on the exchange leaving about 34,000 consumers with no choice.

Only 27 percent of counties will likely have more than three health insurers participating. In 2016, 64 percent of counties had three or more insurers participating.

"In addition to the cost of premiums, insurer decisions around whether or not to offer plans in the exchanges will impact shoppers," said Caroline Pearson, senior vice president of the group. "Consumers will see fewer choices on the exchange again in 2018, with some counties at risk of having no options."

Their analysis also finds that premiums for Obamacare's silver plan will increase at about 18 percent on average in 2018. The group compiled this data based on insurers who have filed their rate increases, noting that many have experienced uncertainty due to the future of the cost-sharing reduction payments. These subsidies were put in question after two House committees said that payments were being made unconstitutionally because they were made without an appropriation from Congress.

"The debate over the Affordable Care Act and cost sharing reduction funding casts uncertainty over the market," said Dan Mendelson, president of Avalere. "But despite all of this activity, the vast majority of consumers will still have commercial exchange options in 2018."