Donald Trump’s proposed health carepolicies have been largely vague, but the few specifics he hasoffered have led at least one expert to conclude that millionswould lose coverage if the bombastic billionaire got his way aspresident.

The study from the nonpartisan Center for Healthand Economy found that 18 million would lose coverage, andpremiums in the individual insurance market would likely decline aswell.

Much of the loss in coverage would come from Trump’s plan to turn Medicaidinto a block grant program, which would likely deal a big blow tothe millions who have gained Medicaid coverage as part of theAffordable Care Act’s expansion of the low-income health insuranceprogram.

Trump’s support for turning Medicaid into a block grant is oneof the few concrete areas of agreement he has had with HouseSpeaker Paul Ryan, R-Wis., on reining in social welfareprograms.

Trump has been steadfast in his support for maintaining Medicareand Social Security as they currently exist, in contrast to Ryan,who has proposed reforming the programs by raising the age ofeligibility for benefits and by partially privatizing theprograms.

The insured rate would also drop because Trump’s plan wouldeliminate the individual mandate to purchase insurance. Andalthough Trump has promised that his plan would provide universalcoverage, regardless of preexisting conditions, the study found noevidence of such a guarantee in the plan that Trump hasreleased.

"You are going to get a lot thinner coverage both in terms ofhigher deductibles and fewer benefits," John Holahan of the UrbanInstitute think tank told Yahoo News. "The policy is bad for peoplewith high risk, and good for people with low risk."

The repeal of the ACA, as well as the associated rules imposedon the insurance industry by the Obama administration in recentyears, would allow insurance companies to sell plans that fall wellshort of what is commonly accepted as comprehensive medicalinsurance.

Insurers already won a victory on that front last week, when afederal court struck down an Obama administration rule thatprohibited insurers from selling “fixed indemnity” plans asstand-alone policies.