Residents in every U.S. county are expected to have at least one insurer to buy coverage from on Obamacare's exchange when open enrollment starts in November, but several difficult decisions lie ahead for customers, particularly those who will not receive any help paying for their premiums.

Those customers are facing significantly higher costs for their policies, and those whose current insurer isn't providing coverage for 2018, whether subsidized or not, likely will have to change doctors and hospitals to make sure they aren't slammed with high out-of-pocket medical expenses.

Solutions to those troubles will be explored by Congress when lawmakers return to the Capitol in September, but already federal data show that 2.7 million of those who will buy coverage on the exchange are facing the prospect of being able to select a plan from only one insurer for next year. Many of the insurers that filled "empty counties," meaning those where insurers initially said they wouldn't sell plans, significantly increased premiums from what customers are paying this year.

Insurers have requested double-digit increases in some states, though the rates still need to be approved by insurance commissioners. The situation could change quickly: A Congressional Budget Office analysis projected that rates would be roughly 20 percent higher if insurers don't receive cost-sharing reduction payments, funds that the Trump administration has not said it would continue and which are mired in both a political and legal battle.

Insurers alternatively could decide not to sell plans in certain counties, causing more people to face the prospect of having only one company to choose coverage from, or none at all.

"Nearly half of counties across the nation only have one health insurance option which, by definition, is not a choice," said Matt Lloyd, spokesman for the Department of Health and Human Services. "Under Obamacare, Americans were promised access to a wide variety of high-quality, affordable coverage options. Obamacare has failed to deliver – an unfortunate reality for the American people who are required to buy Washington-approved health insurance or pay a fine."

For most customers who buy coverage on the exchange, roughly 9 million people, the increases will not make a difference to their pocketbooks because the federal government contributes subsidies to pay for their premiums. That keeps costs relatively consistent year to year.

For as many as 9 million more people, however, premium increases are set to have a deep financial impact. The cutoff for when people have to pay full price is at a gross income of $48,240 a year for an individual and $98,400 for a family of four.

Some options exist for people who are close to the threshold. If they are self-employed and have some control over their income, they can try to make a little less to take home more money at the end of the day. They also can deduct certain expenses so that their gross income would qualify them for subsidies, or they can choose a different health plan level.

But for many, the costs are becoming difficult to stomach.

For Carol Ray, 62, who lives in Arizona and whose gross income is $70,000 a year, premiums that she pays this year doubled to $1,182.78 a month. The bronze-level plan carries a $6,500 deductible for an individual or $13,100 for her and her husband. The Washington Examiner verified the charges.

"I can write the check for it, so I guess you could say it's affordable," Ray said. "What I vacillate on is whether it's reasonable ... I'm not of unlimited funding ... At some point, I have to be pretty careful about what I'm spending."

Her travel plans to see her son, who is a military service member in Germany, for instance, is in a precarious position, she said. She would like to see Congress fix the healthcare law and even consider a single-payer system.

"I'm a middle-class American," she said. "Am I willing to pay more to help those who need insurance who don't have access at all? Yes. It just doesn't feel very even to those of us footing the bill outright."

The Senate Health, Education, Labor, and Pensions Committee is meeting in September to try to come up with solutions to high premiums and may decide to appropriate the cost-sharing subsidies. It's not clear what other moves they will make, but committee Chairman Lamar Alexander said in a recent statement that he is concerned about how higher premiums will affect certain enrollees.

"Eighteen million Americans, including 350,000 Tennesseans – songwriters, farmers, and the self-employed – do not get their health insurance from the government or on the job, which means they must buy insurance in the individual market," he said. "My goal by the end of September is to give them peace of mind that they will be able to buy insurance at a reasonable price for the year 2018."

Final contracts are due Sept. 27, and a senior Senate Democratic aide said having a bipartisan solution by mid-September was reasonable.

Though the changes Congress makes may not drastically alter many of the insurance rates given the short timeline, it could keep the landscape from getting worse.

"Insurers who had filed but had one foot out the door might stay in," said Cynthia Cox, associate director for the program for the Study of Health Reform and Private Insurance at the Kaiser Family Foundation. "It's probably too late for insurers who have already said they will exit because they would have to go through the rate review."

Insurers have been wary about selling Obamacare exchanges plans because they have lost hundreds of millions of dollars after a sicker population signed up for coverage than they had anticipated. As the Trump administration continues to be vague about whether it will enforce the individual mandate and whether it will pay insurer subsidies, many cited the uncertainty as another reason for dropping out.

Those who stayed, or entered more counties, tended to have not only higher rate requests but also a narrower network of healthcare providers.

Adam M., 34, has had to change health insurance providers each year since Obamacare started. He is self-employed and works in e-commerce in Texas, and pays $510 a month for coverage for him and his daughter. He and his wife make about $100,000 a year, and she has coverage through her employer, which does not offer spousal coverage.

His premiums could increase next year by as much as 26.4 percent, according to reports.

"I make too much money to qualify for a subsidy, which I'm fine with in the grand scheme of things," said Adam, who requested to withhold his last name for privacy reasons.

Still, he hopes he will be able to keep the same doctor next year for his daughter, who is turning three. He had to buy a separate plan for her this year so that she could stay with the same physician she has had since birth, whose offices are near their home.

For healthy people who see doctors only occasionally, narrower networks with different providers don't matter as much and can help keep premiums down from what they would be with a broader network. But to patients with serious conditions that need regular care, the change from a team of medical providers they trust can cause significant disruption.

"They may have to switch plans and that can often mean switching doctors and hospitals," Cox said. "And if you're in the middle of treatment, that can be a hardship."

The parents of Jason, 31, who asked to withhold his last name to protect their privacy, had to buy a more expensive healthcare plan, of $150 more a month, to keep coverage for his mother's oncologist, whom she had been seeing once a year because she had ovarian cancer.

Monthly premiums cost $1,173.20, with a $12,000 deductible for the family. Filings show that Blue Cross Blue Shield, the plan they are now on, has requested rate increases of 26.9 percent with cost-sharing subsidies and 31.7 percent without them. The family owns a home-building business where they earn roughly $80,000.

"They are very frustrated about the cost. It's almost 1.5 times what it was before the Affordable Care Act, when they had one more person on their plan than they do now," said Jason, using the formal name for Obamacare.

Ray had to change plans this year after her insurer stopped selling plans in Arizona and the only doctor in her network was 40 miles away.

"I can't say there is very good continuity of health," she said. "I'm in very good health. If I were not, it would have been pretty disruptive."

Still, she said she knows that her husband, who has cancer, would be uninsurable without Obamacare, which prohibits discrimination against people with pre-existing illnesses. He currently receives additional coverage under Medicare for disability.

"If I gamble, they would take our home and anything else. I would go bankrupt, and that's why we have the Affordable Care Act," she said. "I'm unwilling to play that gamble."