Aetna’s announcement that it’s largely ditching Obamacare has left affected patients scratching their heads to figure out how they’re going to cover their medical expenses.

An estimated total of 167,600 patients in the 11 states from which Aetna is pulling back are getting dropped, mostly in southern and rural areas. The move cuts the number of counties covered from 778 to 242 — many of which will now have just one single carrier. One county, Pinal County in Arizona, will have zero, becoming the first in the nation to have no Affordable Care Act providers.

“Following a thorough business review and in light of a second-quarter pretax loss of $200 million and total pretax losses of more than $430 million since January 2014 in our individual products, we have decided to reduce our individual public exchange presence in 2017,” Aetna said in a statement.

The company said riskier patients than it had expected had signed up and pushed premiums too high to be sustainable in many areas.

Aetna’s withdrawal itself will affect relatively few patients — 1.02 percent of the total 16.4 million estimated population insured under Obamacare — but it’s the third major provider to retreat from the nationwide plan. Policy analysts say this worrisome trend reduces competition and limits patient choices.

“It’s a burden on a process supposed to increase competition,” said Dave Mordo, chairman of the National Association of Health Underwriters’ Legislative Council. “Your shopping limitations increase by a lot.”

Aetna customers who got their insurance through work or on a private exchange are not affected; only those who who purchased it through Obamacare and don’t live in Delaware, Iowa, Nebraska or Virginia.

Those patients should head right back to where they started, said Cynthia Cox, a health policy analyst with the Kaiser Family Foundation and hit HealthCare.gov, the government’s one-stop shopping site for public health exchanges.

Cox recommended entering in your financial information again because if your money situation has changed it can change your premiums.

When you’re looking at the other plans on the market you’ll want to check to see if your doctor and specialists are covered under the new plan, she said. Call your doctors and hospital or health insurance broker to make sure you can stay with the same health care providers.

Also, search for the prescription drugs you know you’ll be taking next year to make sure they’re covered under the plan.

Although most premiums were already expected to rise as part of the 2017 enrollment, the good news is that your monthly outlay won’t be further affected by Aetna’s withdrawal.

“The diminished competition is certainly a concern for premiums,” said Cox. “But there are mechanisms in place to keep insurers from charging unjust premiums.” She cited state and federal government rate reviews and a reimbursement plan if it’s discovered that an insurance provider is charging too high a rate compared to how much it pays out.

For these customers, since what they pay is largely based on their income and family size, a low-cost “silver” plan will be much the same at another carrier. “They’re going to pay about the same amount they’re paying now,” said Cox.

It may also be worth it to read the paper, said Mordo. With so many payers leaving the exchanges, patients “might want to also check if there are news items. For instance if we read something about [an insurance company’s] profits being down, that might be an omen for the future.”