Having dodged multiple failed repeal-and-replace attempts this year, the Affordable Care Act, commonly known as Obamacare, will enter its fifth open enrollment period this week for individuals and families looking to buy health insurance plans for 2018.

But consumers should be aware of several big changes: this year's shortest-ever enrollment period, planned outages to the Healthcare.gov website, and big premium price hikes that will be felt most acutely by those whose incomes disqualify them from receiving the health care law's government subsidies.

Open enrollment on Healthcare.gov launches Nov. 1 and ends Dec. 15. That is half as long as last year's period, which ran through January. Those who miss open enrollment can only sign up under special circumstances, such as the loss of a job.

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"Every year thus far they've extended the deadline, but this year they changed it intentionally to get people to enroll by Jan. 1," said Catherine Cooper, legislative chair for the Michigan Association of Health Underwriters.

There is also less marketing money for open enrollment and less funding for assistants called "navigators" to help people make coverage decisions. And the Healthcare.gov website will now be offline for maintenance from midnight until noon on every Sunday, except for the final Sunday on Dec. 10.

Yet the most consequential change could be the higher sticker price for health insurance policies: The average price in Michigan of an individual plan will jump a record 26.9% for 2018. That compares to an average 16.7% increase from 2016 to 2017, and 6.5% from 2015 to 2016.

Roughly 300,000 Michiganders are expected to get enrolled in a plan during open enrollment, down from previous years and about 3% of the total population.

To be sure, most people who buy health insurance on the Healthcare.gov exchange are insulated from the full effect of the skyrocketing premiums. That is because the Affordable Care Act's tax credit subsidies increase as the premiums increase in order to keep the plans affordable.

In 2016, about 88% of Michiganders who bought policies through the exchange received some tax credits, according to data from the U.S. Department of Health and Human Services. The tax credits are offered to those who make up to 400% of the federal poverty level ($48,240 in 2017 for an individual; $98,400 for a family of four.)

Taxpayers ultimately foot the bill for these subsidies.

"In the end, taxpayers overall are paying more as a result" of rising insurance premiums, said Megan Foster Friedman, policy analyst at the Center for Healthcare Research & Transformation in Ann Arbor.

Those individuals and family households that make too much money to qualify for the tax credits must pay the full price of their health insurance plans. If that price feels too high for them, they can opt to go without health insurance and instead pay the health care law's penalty for lacking insurance.

The tax penalty is 2.5% of household income or $695 per adult, whichever is higher. The IRS recently warned it won't process income tax returns that don't disclose the filer's health insurance status, a policy that was widely interpreted as meaning the IRS will still enforce the health care law's individual mandate to have insurance.

There will be eight insurance companies in Michigan this year offering products on Healthcare.gov, down from 13 during the first enrollment period in 2013-2014. The most recent insurer to drop out of the individual market, Health Alliance Plan, cited unstable premiums and uncertainty about federal funding and enforcement of the mandate requiring everyone to get insurance.

Consumers in some parts of the country, typically rural communities, will find only one insurance company serving their area. In Michigan, all counties this year will have at least two insurers.

Detroit resident Dwight Dexter, 58, a self-employed Internet developer, has yet to decide whether he will buy health insurance during open enrollment or skip it and pay the penalty.

He said he doubts he will qualify for a tax subsidy on Healthcare.gov because his income is too high. Yet he doesn't expect to comfortably afford the full cost of a health insurance plan that, in his opinion, would be worth having.

Dexter noted how many of the cheaper health plans sold on the exchange carry high deductibles that people must spend on their own before the insurance kicks in. For instance, the average deductible this year for a "silver"-tier plan on the exchange was $2,800. (The tiers range from bronze and silver to gold and platinum.)

So Dexter doesn't wish to pay hundreds of dollars each month for insurance that wouldn't be useful for routine health care expenses.

"I know I'll need it when I get hit by a bus," he said. "But if I pay $600 a month for that kind of coverage, then I'd have to pay all my health care expenses anyway because the deductible is, you know, ridiculous."

Deter, who recently moved to Michigan from San Diego, said he has gone without health insurance for most of this year.

"I can go see a nurse practitioner for $50 if I need prescriptions or something — that's what I've been doing," he said.

The year-over-year price hikes for insurance plans is especially high this year, due in part to the Trump administration's announcement this month that it will halt payments to insurance companies for a type of subsidy called cost-sharing reduction payments.

Those payments reimbursed insurers for offering very low deductibles and co-payments on plans to individuals and families with incomes up to 250% of the poverty line.Consumers who chose these plans and qualified for tax credit subsidies won't be priced out of insurance for next year, as their subsidy will grow to cover the higher premium costs.

Still, the loss of cost-sharing payments prompted insurance companies to raise the sticker prices on their 2018 plans even higher to make up for the lost money.

"Now insurers won't be getting these payments from the federal government to help cover the costs," said Friedman, the health care policy analyst. "And so to account for this loss of funding, carriers are essentially raising premiums for the plans that they're offering on the marketplace."

Friedman suggested that everyone shop around on Healthcare.gov this enrollment period rather than simply auto-enroll in their current plan, because prices will have shot up for those "silver"-tier plans that benefited from the now-cancelled cost payments.

"You might be able to get a gold plan for not much more than a silver," she said.

Steven Gutterman, 59, of Ann Arbor, buys his health insurance on Healthcare.gov and was upset by the news about the discontinued cost-sharing payments.

He said he currently qualifies for a $512-per-month subsidy for an insurance plan that he pays just over $100 a month for. He is hoping to find a similarly affordable policy once open enrollment starts again.

"Let's say I'm apprehensive," said Gutterman, who is self employed. "Right now I have decent insurance coverage that's at a price I can afford. There's no choice but to wait and see" the new prices.

He added, "As far as I'm concerned, the Republican Party owns this because they campaigned on getting rid of Obamacare."

After vowing for years to "repeal and replace" Obamacare, Republicans in Washington tried several times this year to rewrite the Affordable Care Act, but each effort fell just short of the Senate votes it needed. Critics contend that the Trump administration, presently stuck with Obamacare, is trying to weaken it through measures such as cutting its marketing funds and cost-sharing payments.

"We'll let Obamacare fail and then the Democrats are going to come to us," Trump said in July, referring to his desire to see Democrats cooperate with Republicans for an Obamacare replacement.

There is currently bipartisan legislation that would restore cost-sharing payments — what Trump has called a "short-term fix" — but it's unclear whether that bill has enough support.

The Trump administration has reportedly cut funds for marketing and promoting ACA enrollment to $10 million from $100 million. And additional funding cuts have been made to organizations that help people sign up for health plans on Healthcare.gov through assistants called "navigators."

Two Michigan organizations — Enroll Michigan and ACCESS, the Arab Community Center for Economic and Social Services in Dearborn — saw significant cuts in their grants for providing sign-up assistance.

Enroll Michigan saw its enrollment funds cut nearly 90% from last year to about $130,000 and ACCESS took a 36% cut to about $352,500, according to representatives of those organizations.

Dizzy Warren, executive director of Enroll Michigan, said her organization has about 80 navigators and helped nearly 50,000 people last year sign up for health insurance.

The number of people needing assistance has gone down, she said, as people have grown more familiar with the health insurance website and how insurance works, she said. But older adults and non-native English speakers often still need some help navigating the many options.

Despite the recent funding cut, Warren said Enroll Michigan doesn't anticipate a shortage of available assistance this year because partner organizations can continue to supply navigators and pay them through other funding sources.

"I don't think consumers will notice any difference as to the availability of navigators in their community," she said.

Contact JC Reindl: 313-222-6631 or jcreindl@freepress.com. Follow him on Twitter @JCReindl.

How to sign up:

Those shopping for coverage on the Healthcare.gov marketplace can also apply by mail, over the phone at 800-318-2596, or in person with the help of a local navigator. Anyone who bought a plan last year through the marketplace will be auto-enrolled in the same plan, unless they chose a different plan by Dec. 15. If an insurer is discontinuing a plan, those currently in the plan will be auto-enrolled into a similar plan by the same insurer.

Navigator programs and other assistance includes:

ACCESS (Arab Community Center for Economic and Social Services): 888-670-6798

Enroll Michigan: 517-512-3141

Beaumont Health System will have enrollment events at its Dearborn, Farmington Hills, Grosse Pointe, Royal Oak, Taylor, Trenton, Troy and Wayne hospitals. Information is available at Beaumont.org/marketplace or by calling 800-582-1101

Midwest Asian Health Association (MAHA): 312-225-6806

Forest County Potawatomi Community: 715-478-7200

Insurers offering plans on Healthcare.gov: