On the campaign trail, Donald Trump was clear that his priority for health care would be to repeal Obamacare. But after meeting with President Obama this week, he took a softer tone in an interview with The Wall Street Journal, saying that he’s looking into preserving some aspects of the law. Specifically, he expressed interest in two of the law’s most popular provisions: not allowing insurers to discriminate among buyers based on pre-existing health conditions and allowing young adults to stay on their parents’ health plans up to age 26. That still leaves a lot of unanswered questions about what he plans to do with the Affordable Care Act.

Although the law has been relatively unpopular since it passed, many aspects of it have been well received. In addition to those that Trump mentioned to the Journal, Medicaid expansion, which extended government insurance to more low-income people, and subsidies for people who buy insurance on marketplaces created under the law, have been viewed favorably in various surveys. A lot of Americans’ feelings about the law as a whole appear to be wrapped up in how much they trust the government, as Dan Hopkins detailed for us in 2014, well before Trump won the presidency on a campaign of change in Washington.

PROVISION FAVORABLE RATING Extension of dependent coverage to age 26 80% Close Medicare “doughnut hole” 79 Subsidies for low- and middle-income people to buy insurance 77 Eliminate out-of-pocket costs for preventive services 77 Medicaid expansion 74 Insurers can’t discriminate based on pre-existing health conditions 70 Medical loss ratio 62 Increase Medicare payroll tax on people who make more money 56 Requiring most people to have insurance or be fined 35 Most Obamacare provisions test well Survey from March 2014 Source: Kaiser Family Foundation

There is a relatively straightforward path for Trump and Congress to kill off certain aspects of the law while preserving others. They can use a budgetary process known as “reconciliation” to defund pieces of the law. We can look at themes from Trump’s campaign and other Republican proposals for hints of what that might look like.

As Sarah Kliff detailed at Vox, a reconciliation bill that would cut most of the financial support for the ACA passed the House and Senate before being vetoed by Obama earlier this year. Trump and Congress could resurrect that bill to kill Medicaid expansion, federal subsidies for insurance, tax penalties for not having insurance and taxes created to fund the law. Or they could write a new reconciliation bill.

(It’s not a certainty that any iteration would pass — assuming that all Democrats vote the party line, it would take only two or three of the 19 GOP senators from states that expanded Medicaid to defect on a reconciliation to prevent even a defunding of key parts of the legislation.)

Assuming that a reconciliation bill did pass, however, piecemeal changes would likely cause a lot of instability. The law is built on interlocking provisions; removing one puts pressure on others. That’s what happened when the Supreme Court made the Medicaid expansion optional for states, leaving 2.5 million people in states that chose not to expand in what has been called the Medicaid gap: too poor to be eligible for the marketplace subsidies but ineligible for Medicaid. Leaving in place the mandate for insurance companies to cover people with pre-existing conditions, as Trump said he’s considering, while getting rid of either the individual mandate — the requirement that people get insured — or the subsidies that motivate low-income healthy people to join the insurance rolls could also create instability in the insurance market. Without the necessary mix of healthy people in a plan to offset the costs of insuring people with pre-existing conditions, premiums rise, becoming unaffordable for everyone.

An estimated 22 million people would lose their insurance if Congress and Trump implemented the changes outlined in the most recent reconciliation bill. Even if Trump tries to hang onto the provisions he mentioned after meeting with Obama, it’s unclear what he might do to keep all those Americans insured. Looking at his campaign stump speeches, and proposed legislation from other Republicans, we can make some educated guesses about what might happen.

Trump’s proposals probably won’t include an individual mandate or a Medicaid expansion as it currently exists under the ACA.

Trump has said he wants to dismantle several key elements of the law, chief among them the individual mandate. He’s also said he’d like to use “block grants” that would provide a fixed sum, with fewer federal regulations, to states to fund Medicaid. It’s an idea that also features in House Speaker Paul Ryan’s health care proposal. That’s different from Medicaid expansion under the ACA, which requires that states cover everyone below 138 percent of the federal poverty line. It’s not clear how many of the millions of people who currently have Medicaid coverage under the ACA expansion would remain eligible for government assistance.

The individual mandate is a little more complicated. At one point, it was seen along most of the political spectrum as a promising way to reduce the number of uninsured people in the United States; requiring healthy people to sign up for coverage was supposed to ensure that premiums were affordable. The idea was originally floated by the conservative think tank the Heritage Foundation and was first brought to Congress by Republicans in the 1990s. The mandate has since become one of the most despised aspects of the law.

But there isn’t a clear policy proposal with bipartisan support for how to get more healthy people into the insurance market in the absence of an individual mandate and insurance subsidies. Trump has proposed creating high-risk pool insurance programs, essentially plans that people with pre-existing conditions can buy into. These types of plans existed in many states before the passage of the ACA and by design are not self-sustaining because members use significantly more health care than they can afford. That means they require significant federal dollars ($25 billion in the case of a plan from Ryan), which is one of the many reasons high-risk pools are divisive among Republican lawmakers.

Health savings accounts could become a more prominent feature of health insurance coverage.

Health savings accounts, which allow people to make tax-free deposits into accounts that can be used to pay for health expenses, were a major part of Trump’s campaign platform. He’s likely to promote them, but it’s not clear how they would affect insurance markets in the big picture. They can be a great option for higher-income people but do little to help low-income families who can’t afford to save and earn too little to benefit from the tax break.

Providers will probably be forced to be more transparent about prices.

Trump has said repeatedly that providers should be transparent about the cost of services and that patients should be able to shop for care based on prices. That would benefit consumers, but it’s not as straightforward a fix to health care spending as it sounds. Shopping around for health insurance isn’t like buying a toaster — people take many things into account when choosing a doctor that have little to do with price (specialization, convenience and having an established relationship are just a few). And the insurance, hospital and pharmaceutical lobbies are all likely to push back hard against any efforts toward price transparency.

All of this uncertainty makes for a strange year to come. “The next year is going to be very awkward in the health insurance market,” said Larry Levitt, a senior vice president at the Kaiser Family Foundation, a nonpartisan health care think tank. “Until the ACA is actually repealed, all its rules and benefits are still in place. There’s an open enrollment period going on right now. In the spring, insurers will have to decide whether to participate in the marketplace in 2018 and will have to file premiums.”

I’ve written in the past that I was skeptical of whether it was feasible to just repeal the Affordable Care Act, but my skepticism was rooted in the unprecedented nature of cutting millions of people out of their insurance plans. “We have no precedent for unwinding a public benefit affecting as many people as the ACA,” Levitt wrote on Wednesday. But if this election has taught us anything, it’s that precedent does not predict the future.