White House backs conservative health plan, but GOP leaders are leery

“People who have higher health care needs and need more comprehensive coverage would choose A.C.A.-compliant plans,” said Cori E. Uccello, a senior fellow at the American Academy of Actuaries. “People who are healthy now would tend to choose noncompliant plans with really basic benefits. People who want or need more comprehensive coverage could find it out of their reach, because it might become unaffordable.”

Some Senate Republicans share that concern. The proposal, they say, would undermine their contention that they are preserving protections for people with pre-existing conditions.

“I believe it would lead to adverse selection in the marketplace,” Ms. Collins said. “It would also vitiate the important consumer protection of having a prohibition against annual and lifetime caps” on benefits.