MNsure is counting on a big second half to the current open enrollment period to reach its goal of 67,000 sign-ups for private health insurance this year.

Outside experts differ on whether MNsure actually will hit the mark it says it needs to meet its current budget targets. But there's agreement about the challenge for the exchange between now and Feb. 15, when the open enrollment period closes.

"They have a huge hill to climb in terms of private enrollment," said Julie Brunner, executive director of the Minnesota Council of Health Plans, a trade group for health insurers. "Their work is absolutely cut out for them, and they know it."

On Monday, health exchange officials said that 31,159 people had enrolled in private plans by Dec. 31, which was halftime for the current three-month open enrollment period.

The tally is less than half of MNsure's private enrollment target, but spokesman Joe Campbell said the exchange expects to add another 9,000 people over the next week or so through a "passive enrollment" process that applies to certain subscribers.

"With passive enrollments included, we're a little more than halfway toward meeting our revenue and enrollment projections," Campbell said. "And we're about halfway through the open enrollment period, so we feel really good about that."

For a strong second half, MNsure expects to increase outreach to people who bought coverage last year from PreferredOne, Campbell said. The carrier was the most popular MNsure option last year, but is not offering policies through the exchange in 2015.

Many of those subscribers could save big money on the exchange, MNsure says. Federal tax credits that discount premium costs are available on MNsure, but not in the off-exchange market.

MNsure's advertising campaign will grow in the coming weeks, Campbell said, and the health exchange will be spotlighting enrollment centers that can help people get coverage. The exchange also plans to target groups such as service industry workers where many people lack coverage.

"We're pulling out all the stops now," Campbell said. "We know that there's only six weeks left, and we're going to work like crazy to meet these goals."

After the current open enrollment period ends on Feb. 15, people who lack health insurance could be subject to a tax penalty.

"We feel like there will be a surge again this year, driven primarily by the penalty and by the deadline," Campbell said.

Heidi Michaels, an insurance agent with Dyste Williams in Minneapolis, said she's skeptical. Most who wanted to buy coverage for 2015 have already done so, said Williams, who is president-elect of the Minnesota Association of Health Underwriters, a trade group for health insurance agents.

Last year, about 48 percent of those who bought private coverage through MNsure did so during the second half of the open enrollment period. But Michaels said she didn't expect a repeat this year because a chunk of late shoppers last year did so due to late drops in employer-sponsored coverage. Those folks already have renewed coverage for 2015, Michaels said.

Another factor is that the current open enrollment period is shorter.

"This year, it's only a month and a half, whereas last year it was through the end of March," Michaels said. Of the odds that MNsure will sign up 67,000 for private coverage by mid-February, Michaels said: "Not a chance."

Jim McManus, a spokesman for Blue Cross and Blue Shield of Minnesota, said officials with the Eagan-based insurer believe the majority of the company's MNsure enrollment would be for plans with a Jan. 1 start date. But McManus added: "There are still 2014 MNsure member auto-renewals that haven't been applied to our overall enrollment numbers. That should move the needle somewhat when the final tally is made."

Dan Schuyler, a senior director with Leavitt Partners, a consulting firm in Utah, said he thought the enrollment tally thus far means MNsure will easily enroll 60,000 in private coverage by Feb. 15. If another 9,000 people come through passive enrollment, "it's icing on the cake," Schuyler said.

After sizing up the latest numbers, Caroline Pearson with Avalere Health, a consulting firm in Washington D.C., wrote in an e-mail: "It appears that MNsure is on track."

Julie Sonier, a health policy researcher at the University of Minnesota, also said MNsure seems to be on track, but added: "We really won't know until mid-February."

MNsure is focused on getting people into private health plans both to lower the state's uninsured rate, and to secure the financial future of the exchange. Operating costs at the exchange are funded in part by withholding 3.5 percent of premiums for each private policy sold through MNsure.

Revenue also comes from the state Department of Human Services, which manages the Medicaid and MinnesotaCare public health insurance programs.

People can use MNsure to enroll in the public programs, in addition to private policies. Sign-ups in public health insurance programs since Nov. 15 include 26,540 new enrollees in Medicaid, and 11,152 people who newly selected MinnesotaCare coverage, according to numbers released Monday.

Minnesota launched the MNsure exchange last year to implement the federal Affordable Care Act, which requires almost all Americans to have health insurance.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck