Nearly 137,000 Minnesotans have enrolled in coverage through the state's online health insurance marketplace, MNsure officials said Tuesday.

MNsure's board set a goal of 135,000 enrollments about two weeks after the troubled website went live in October. But the number of Minnesotans who enrolled in private insurance plans is much lower than MNsure officials expected, and the number of those who enrolled in government plans is higher.

There's real money at stake in the eventual enrollment mix, as MNsure's future funding will come from a percentage of the premium dollars paid to commercial health plans. If fewer people enroll in those plans than MNsure anticipated, the agency will receive less funding. As of Tuesday, there are far fewer people enrolling in commercial plans than MNsure's board envisioned last October when the panel set enrollment goals.

With less than a week left in the open enrollment period, only about 26 percent of people securing coverage through MNsure have signed up for commercial health plans. That's well below the goal of 58 percent.

"That's largely a function of the fact that we simply didn't have a lot of information upon which to estimate what the mix would really look like," MNsure Interim CEO Scott Leitz said. "So we're going to be working really hard between now and end of open enrollment to make sure we get as many folks enrolled in whatever programs they're eligible for and we're certainly hopeful that people who are eligible for commercial coverage will come in."

Those who fail to obtain health coverage could face a potential penalty of $95 or 1 percent of their income, whichever is greater. Moreover, those who buy health insurance on the individual market won't be able to enroll again in coverage until mid-November unless they fall under an exception — a qualifying "life event" such as a birth of a child; a marriage or divorce; or job loss.

Meanwhile, MNsure leaders say consumers who make a good faith effort to enroll in health coverage through the website can avoid a penalty even if they don't complete the process by the deadline of midnight March 31. They say given a likely rush of last minute enrollments, MNsure will offer an extension where consumers have started the process but couldn't complete enrollment before the clock ran out.

M.I.T. economist Jonathan Gruber said he's surprised the number of private insurance enrollments through MNsure isn't lower given the website's serious and protracted troubles.

"Minnesota's clearly had problems with its website as a number of states have, including my own state of Massachusetts," Gruber said. "So in some sense, I'm actually encouraged by how much private enrollment they've gotten given the sort of difficulties I've heard about with the website."

Representatives of the Council of Health Plans, a trade group that represents the state's health insurers, agree that the website problems stunted private coverage enrollment. Julie Brunner, the council's director, suspects many people abandoned the website and signed up with insurers directly. But she said it's too early to know how many.

"Until we get through open enrollment and people can actually draw the line and say, 'from this date to this date, this is what the enrollment looked like,' we really won't have those numbers," Brunner said. "I think a lot of people are really interested in them."

Two weeks ago, preliminary budget projections for next year showed a $5 million shortfall. The agency expects to make that up with left-over federal grant funds.

Government-sponsored health plans are by far the most popular coverage through MNsure, accounting for 74 percent of all enrollments. State Human Services Commissioner Lucinda Jesson said there are several reasons for that, among them a new streamlined application process for government programs.

The actual MNsure enorllment rates compared to goals set by MNsure's board. Will Lager/MPR News

When the MNsure website developed serious problems government staffers turned to paper applications, allowing enrollments to proceed. Jesson said many Minnesotans qualify for government-sponsored coverage.

"A sizable majority of the people without health insurance were already eligible for one of our public programs," she said. "So it's good to see that they're starting to sign up."

University of Minnesota Health Economist Lynn Blewett said it's also important to remember that while other states may have a higher portion of private insurance enrollment, they don't have anything like the MinnesotaCare program, the state-subsidized insurance program. In other states people eligible for MinnesotaCare would be buying commercial health insurance known under the ACA as "qualified health plans."

• See enrollment numbers by state

"So if you really want to compare apples to apples, we should really add the MinnesotaCare and the qualified health plans together," Blewett said.

But even if the two pools were combined, MNsure would still fall short of its October targets.

In compiling a preliminary budget for 2015 two weeks ago, MNsure's board estimated that about 40,000 Minnesotans would sign up for private coverage through MNsure's open enrollment this year, followed by an additional 10,000 that would do so over the course of the year.

To date, 36,176 people have signed up for private plans.