BOISE, Idaho — Federal officials say thousands of Idahoans may be eligible for a tax credit if they purchase insurance through the state’s health care exchange rather than skip the marketplace again while picking coverage for 2017.

The U.S. Department of Health and Human Services announced this week that approximately 15,000 Idaho residents bought coverage outside of the Your Health Idaho website with income levels that might have qualified them to receive a tax subsidy.

Only residents who buy their plans on the health exchange are qualified for a tax credit. Health officials say the tax credits were designed to make coverage more affordable and protect consumers from the impact of rate increases.

The HHS report released Tuesday doesn’t estimate how much help these shoppers might receive if they used the exchanges. Both the report and officials with Your Health Idaho didn’t know why residents were buying coverage outside of the exchange. However, a spokeswoman for the Idaho exchange said that officials are continuing to work on education and marketing to encourage as many people to purchase coverage on the exchange for 2017.

Those who buy individual coverage without tax credit help — an estimated 6.9 million people nationwide according to the report — pay the full price of the policy.

More than 100,000 people used the Idaho exchange to buy plans this year. Most of those customers qualified for federal subsidies to help pay premiums because their incomes were too low to pay full price.

The exchange is part of the Affordable Care Act. Idaho was one of a dozen states, as well as the only Republican-dominated state, to launch its own exchange in 2014.

The annual enrollment window for 2017 coverage begins November 1 and runs through next January.