MNsure board members expressed concern Wednesday over a Trump administration proposal that would cut in half the open enrollment period when individuals can buy health insurance coverage for 2018.

The proposal was one of several put forward Wednesday by the federal Centers for Medicare and Medicaid Services (CMS) in hopes of stabilizing the individual market.

Government-run exchanges like MNsure are an option for people who buy individual health plans.

Currently, open enrollment for 2018 coverage is scheduled to run from Nov. 1 through Jan. 31, but the CMS proposal would end the sign-up period on Dec. 15.

"We anticipate this change could improve the risk pool because it would reduce opportunities for adverse selection by those who learn they will need services in late December and January," CMS said in a notice of the proposal. The change also would "encourage healthier individuals who might have previously enrolled in partial year coverage after December 15th to instead enroll in coverage for the full year."

Individual health plans are purchased by people who are self-employed and those who can't get coverage from an employer or government program. The market serves less than 5 percent of state residents.

During a board meeting Wednesday in St. Paul, MNsure Chief Executive Allison O'Toole did not comment on the merits of the proposal, but said the state's health insurance exchange would give it "a very critical look" before submitting formal comments by early March.

Board member Kathy Sheran said a compressed timeline for open enrollment "makes it really difficult for us to do what we need to do for the people in the state." Sheran noted that MNsure in 2016 had to react to market disruptions, such as enrollment caps at health plans and the withdrawal of the market's largest insurer.

Board Chairman Peter Benner said after the meeting that the exchanges already expected to shorten the open enrollment period for 2019. But moving up the process by a year might block people from getting 2018 coverage, he said, noting that thousands who purchased through MNsure for 2017 did so after Dec. 15.

"There's a real issue there as to how we balance the accessibility of this process to average citizens vs., as I understand it, the goal of trying to have a more stable individual market," Benner said in an interview.

Minnesota has seen a lot of instability in the individual market, with big premium jumps and dwindling choices for consumers. Last year, regulators said the market for 2017 nearly collapsed with all carriers threatening a pullout.

While MNsure would be subject to the proposed federal rule for a shorter open enrollment period, the exchange might be exempt from other proposals issued Wednesday because it's run by the state government.

Insurance industry groups applauded the proposed rules from the Trump administration, which include tighter regulations around special enrollment periods that let consumers can sign-up for coverage outside open enrollment.

"The CMS rules are about balance," Jim Schowalter, chief executive of the Minnesota Council of Health Plans, said in a statement. "This is the kind of fine tuning that's been talked about for three years. It is needed to make sure some people don't pay more than their fair share."

Consumer groups, however, sounded alarms.

"Research has continually shown us that Americans are already confused about what and when open enrollment is," said Laura MacCleery, a vice president with the advocacy arm of Consumer Reports magazine, in a statement. "This rule could make it more difficult for healthy, young adults to enroll — making it equally difficult to balance the risk pool and imperiling the market."

Twitter: @chrissnowbeck