Twice as many health insurance shoppers this year have turned to the state's MNsure exchange compared to 2015, likely in response to skyrocketing premiums in the state's individual market.

State officials said Monday that more than 54,000 people purchased through the exchange by Thursday's deadline for coverage that starts Jan. 1, and more than half of them qualified for income-based tax credits that discount premium costs.

While MNsure is growing and the enrollment period isn't over yet, health insurers say they've seen a decline thus far in the larger "off-exchange" portion of the individual market, where people buy policies directly from insurers.

The off-exchange trend could point to continued weakness in the overall individual market, which regulators said was on the verge of collapse this summer.

"Outside MNsure, enrollment is down and we are concerned that it could mean the number of people without health insurance is going up," said Eileen Smith, a spokeswoman for the Minnesota Council of Health Plans, a trade group for insurers.

About 250,000 people buy coverage in Minnesota's individual market, which has been the focus of changes under the federal Affordable Care Act (ACA). Self-employed people and those who don't get coverage from an employer or government program like Medicare buy individual policies.

The market's turbulence over the last few years has contrasted with the experience for most Minnesotans, who have seen relatively slow growth in premiums by historical standards. In the individual market for 2017, insurers are boosting premiums by an average of 50 percent or more.

Action might be needed

Insurers won't know if the ranks of the uninsured are growing until open enrollment ends Jan. 31, Smith said, since people not buying individual policies could be moving to coverage in other markets. But if that's the case, the shift could show "the need for the Legislature to act quickly in 2017 to make sure people can buy insurance on their own," Smith said.

Lawmakers have generally agreed on the need to provide help for the individual market — where financial losses for insurers have caused premium jumps and diminished choice — but they've struggled to get beyond partisan battles in advancing a plan.

So far this year, 61 percent of private health plan enrollees through MNsure have been eligible for tax credits, state officials said Monday. The average monthly tax credit is approximately $634.82 — roughly three times higher than in 2016.

"MNsure is helping Minnesotans protect themselves at a record-setting pace," Allison O'Toole, the MNsure chief executive, said in a statement. "Minnesotans are protecting themselves and their families, tapping into financial help, and avoiding the federal tax penalty [for lacking coverage]."

During the six-week period leading up to the Dec. 15 deadline for coverage that starts with the new year, 54,586 Minnesotans enrolled through the health insurance exchange. During the comparable period in 2015, about 27,000 people enrolled through MNsure in private plans.

MNsure and state regulators haven't released enrollment tallies for the off-exchange portion of the market, but Smith of the Minnesota Council of Health Plans said about 120,000 people have signed up thus far. In March, about 200,000 people were enrolled in off-exchange policies, Smith said.

ACA future in question

Some of the gap should close with sign-ups during the remainder of open enrollment, but insurers have told the Star Tribune that the enrollment pace thus far has fallen short of last year. Individual market shoppers face uncertainty on a number of fronts, since Republicans at the federal level have pledged to repeal and replace the ACA. In St. Paul, lawmakers have talked about rebates to shoppers, but haven't agreed on a plan.

"There is relatively low enrollment activity to date, considering the number of people in individual Blue Cross plans who will need to make a change for 2017," Jim McManus, a spokesman with Eagan-based Blue Cross and Blue Shield of Minnesota, said in a statement.

"With all of the uncertainty surrounding the individual market, it's likely that there is a 'wait and see' dynamic in effect," McManus said. "Since open enrollment goes through the end of January, it's possible that people are waiting to enroll so they don't have 12 months of premium payments in 2017."

A spokeswoman for Bloomington-based HealthPartners said last week that enrollment in individual plans was slower than last year, and slower than expected. Insurance agents say they've seen growing interest among individuals who want to move into health plans for small businesses, although such moves are possible only under certain circumstances.

"In my opinion, we will be lucky if total individual enrollment is holding steady because some people are leaving to take up small group insurance and others may be leaving to become uninsured," Roger Feldman, a health insurance expert at the University of Minnesota, said via e-mail. "Many people will be protected against rising premiums by the rising tax credits, but upper-income individuals will get walloped."

Twitter: @chrissnowbeck