The Trump administration on Wednesday finalized yet another set of new health insurance rules as part of its ongoing effort to roll back the Affordable Care Act s consumer protections and restore the kind of market conditions that existed before the law took effect.

The new rules affect so-called short-term, limited-duration insurance plans , which typically cover far fewer services than comprehensive policies and arent available to people who have pre-existing conditions. The plans, which because of Obama-era restrictions are currently available for only three months at a time, have historically served as a stopgap for people who have temporary lapses in coverage say, because they are between jobs.

Now the Trump administration is undoing the Obama regulations and putting new ones in place. Under the Trump rules, which the administration formally proposed in February , insurers will be able to sell plans that last for 364 days by design, one day short of a year with a possibility of renewing coverage twice.

As a result, consumers in some cases could buy and then hold on to these plans for what basically amounts to three years, making it much easier to use short-term policies as a substitute for the kind of comprehensive coverage available through the Affordable Care Act.

It will be up to the insurers whether to offer renewals and under what conditions, administration officials explained in a conference call on Tuesday night. And states will still retain the right to regulate the plans more tightly, whether that means keeping the Obama rules in place or prohibiting the sale of short-term plans altogether.

But whatever the insurers and state officials decide, the plans are likely to prove popular in some parts of the country and for some consumers.

Their big allure will be their upfront cost. Because short-term plans leave out key benefits and because insurers can exclude people who already have serious medical problems, the policies usually have much lower premiums than plans with comprehensive coverage.

For some people now struggling to pay for insurance, including those who are uninsured because they cannot afford coverage available through the Affordable Care Act, these short-term plans will seem like a big relief a point administration officials stressed Tuesday night.

We do think those plans will be very attractive to those who have been most poorly served by the Affordable Care Act, said Randy Pate , a deputy administrator at the Centers for Medicare and Medicaid Services. He mentioned in particular younger and healthier people who think comprehensive coverage isnt worth the expense. This could be an option for them.

But if people who buy short-term policies get seriously ill, they could end up spending a lot more money on medical care than they would with a comprehensive policy under the Affordable Care Act, because theyll be paying out of pocket for services such as mental health care, maternity care or prescription drugs that short-term plans frequently dont cover completely or simply dont cover at all.

One short-term plan now available in California, for example, limits HIV coverage to just $10,000, according to researchers from Georgetowns Center for Health Insurance Reforms . Treatment for HIV can exceed that amount in just two months.

An existing plan from UnitedHealth will help pay for prescriptions, but only up to $3,000. And it wont cover mental health care at all, except in states that require it.

Many consumers will buy these plans thinking they are getting a great deal, Sabrina Corlette , a research professor at Georgetown University , told HuffPost before seeing the final rule. But if they need health care services and the bills start to pile up, theyll quickly discover that these plans cover very little.

Meanwhile, those seeking out comprehensive plans because they want or need them will discover those policies have gotten more expensive, thanks to the way short-term plans will affect the rest of the insurance market. Some insurance shoppers will have serious, even life-threatening diseases, such as cancer, which will mean their insurance must have a full set of benefits. But those kinds of policies will become more expensive than they can afford.

Its Another Act Of Obamacare Sabotage

The new rules represent one of the most consequential steps that President Donald Trump and his Republican allies have taken in their campaign to dismantle the 2010 health care law known as Obamacare . Although Trump and his partners in Congress have not managed to repeal the law outright, they have weakened its underpinnings in ways that have already affected millions and are now set to affect even more people starting in 2019.

Over the past year and a half, the administration has reduced the funding to promote HealthCare.gov , the federally run online marketplace for coverage, all but certainly reducing enrollment . The Trump administration has also given several states permission to change Medicaid in ways that will make it difficult for some people to enroll or to stay on the program.

In July, the administration announced a dramatic cut in funding for navigators, which are the federally certified organizations that assist people with enrollment.

The Republican Congress has also done its part. Last year, it passed a tax bill effectively eliminating the individual mandate , the financial penalty for people who dont get insurance. Trump promptly signed it, removing a key pillar of the Affordable Care Act that, although unpopular even with many Democrats , encouraged healthy people to get coverage and ultimately kept premiums from going higher.