About 43,000 ObamaCare enrollees are bearing the full cost of their insurance plans after losing the tax credits that are meant to make coverage more affordable.

Those enrollees no longer receive ObamaCare tax credits because they failed to file a tax return for 2014, according to the Department of Health and Human Services (HHS). The number has never before been released.

Losing the tax credit can come with a sticker shock. HHS said in March that the average monthly ObamaCare premium before tax credits was $364, compared to $101 after the tax credit.

The precise number of people who are losing federal subsidies is unclear, ­because even family plans are counted as a single applicant. The number also does not include the 12 states and the District of Columbia that operate their own insurance exchanges.

Still, the IRS warned in July that 710,000 households were at risk of losing ObamaCare subsidies because they hadn’t filed a tax return. After the warning letters went out, the number of households that hadn’t filed dropped.

In October, the IRS flagged about 172,000 ­ObamaCare applicants and notified them they were at risk.

HHS told The Hill that by Jan. 1, because some people fixed the problem and some people had dropped coverage altogether, “less than 25 percent” of the 172,000 applicants were enrolled in ObamaCare without tax credits. That translates to around 43,000 enrollees.

People who are enrolled in an insurance plan can become re-eligible for tax credits by filing their 2014 returns.

HHS said it anticipated the tax return problem and worked to prevent it, including with reminders on HealthCare.gov, the federal ObamaCare portal.

“This is an issue that we’re highly sensitive to,” Kevin Counihan, the CEO in charge of the federal marketplace, told reporters last week. “We’ve enhanced our application with new reminders, new pop-ups and other ways to try to assure people what they need to do to make sure that they comply and file the right forms.”

Other people who failed to follow an ObamaCare tax rule are getting something of a pass from the administration this year.

Those people filed their 2014 tax returns but failed to attach a form that compares their tax credits to their income to make sure they received the right amount of tax credit.

The IRS said Friday that about 976,000 households failed to attach the extra form, known as Form 8962, as of the end of October.