Donald Trump, who vowed during his presidential campaign to repeal and replace the Affordable Care Act, is headed to the White House come January.

The 2010 landmark health insurance law brought about sweeping reform. It changed how hospitals and doctors practice medicine, with a focus on preventive care and cutting waste to lower medical costs. It has insured an estimated 20 million more people nationwide, but with fewer choices for consumers and climbing premiums.

Here's the consensus: Obamacare is likely headed for massive change, if it continues to exist at all. So now what? Crain's talked with five experts to understand what a Trump White House could mean for Obamacare throughout Illinois: Stephani Becker, a senior policy specialist at Chicago-based Sargent Shriver Center on Poverty Law; Geoffrey Manville, a Washington, D.C.-based principal at benefits consultancy Mercer; Larry Boress, CEO of Chicago-based nonprofit Midwest Business Group on Health; A.J. Wilhelmi, CEO of Illinois Health and Hospital Association, a Naperville-based industry lobbying group, and Dan Marino, Chicago-based executive vice president at consultancy GE Healthcare Camden Group.

Here's an edited version of our conversation.

Q: Are there certain pieces of the Affordable Care Act you think are more at risk than others of being repealed, and what does that mean for the local landscape?

Becker: The most important thing to remember about the ACA right now is that 20 million people have coverage and have finally gotten health care, including 1 million in Illinois through the marketplace or through the (Medicaid) expansion, and most of those folks are in Chicago or in Cook County. So that's not going to be easy to take away. . . .It's hard to say what the president-elect will or will not shift to, but in some of his policy speeches he has indicated he wants every American covered.

Manville: The Cadillac tax (on generous health plans offered by employers) is certainly one of the leading provisions marked for repeal.

Q: Illinois is one of more than 30 states that send consumers and small businesses to the federal exchange, HealthCare.gov, to buy health insurance. Many insurers have fled the exchange, including, in Illinois, such national carriers as Aetna and UnitedHealthcare, after big financial losses. What do you think the future holds for the online marketplace? Will more insurers feel welcome to participate with a new leader in the White House, or will choices for consumers shrink even more?

Becker: I think 2017 is a really important year in terms of whether the carriers make profits. I think it kind of comes down to that. It's a business decision whether to come in.

Manville: One big question going forward is will Republicans agree to make legislative fixes to the exchanges in the meantime before they get their ducks in a row for full repeal and replacement? That could be a pretty substantial fight within the Republican Party. . . .But there's a lot of pressure from consumers and carriers to make changes. We've seen carriers pull out of a lot of the exchange markets, and that's an immediate problem that may demand immediate attention.

Q: Obamacare fueled many behavioral changes in Illinois health care. Hospitals and doctors lose money if their patients get unnecessary care. The state expanded the Medicaid program for the poor and disabled. Consumers armed with high-deductible health plans saved money if they shopped around for deals on medical care. Do you see these efforts continuing?

Boress: Oh, absolutely. . . .People (having) to start shopping just like they do for a TV or a car or an appliance, knowing the difference not only in quality and cost, I think that's only going to grow as more employers adopt high-deductible plans.

Wilhelmi: Given the election last night, I think there is some degree of uncertainty. But at the end of the day, our hospitals have certainly embraced the delivery and payment reforms.

Q: We've seen a wave of consolidation in the Chicago area among hospitals and doctors as Obamacare mandated keeping people healthy while spending less. But what impact could a Trump White House have on mergers?

Marino: I think that at the end of the day, there's still that underlying principle that we need to reduce or slow the rise of health care costs. . . .I think we're going to see this continued push for integration. I think one of the biggest issues the Trump presidency is going to have to tackle is where the commercial payers fit into this, where pharma fits into this, being able to manage some of the drug costs, and those types of things.

Q: Will Chicago-area hospitals still embrace change?

Marino: I definitely think they will because if the commercial carriers still move down the direction of wanting to pay more for value rather than fee for service, then I absolutely think these organizations are going to have to focus on how do they best position themselves. I just think there's too much momentum for it not to occur.