MNsure officials say call volumes, wait times and website functions have been back to normal the last two days, as the state's health insurance exchange shakes off what a top official called "suspicious" behavior earlier this week on the phone lines.

On Tuesday, Gov. Mark Dayton alleged that the MNsure call center was clogged by robocalling. State IT officials issued numbers late Wednesday showing there were about 50,000 call attempts at MNsure by 9 a.m. Tuesday, compared with just 1,600 by the same time Wednesday morning.

The lower call volume continued Thursday, state officials said, adding that a new story is emerging of robust enrollment activity.

"We've helped more Minnesotans than we have in any two-day period in our history," said Allison O'Toole, the MNsure chief executive. "We've now enrolled more than 10,000 Minnesotans. That's a benchmark that we didn't hit until after Thanksgiving last year."

Enrolling 10,000 people in private health insurance coverage over two days is an impressive tally, said Charles Gaba of ACAsignups.net, a Michigan-based website that tracks enrollment through exchanges across the country.

Gaba noted, however, that Minnesota has unique drivers for people to shop early, since sign-ups are being capped in most health plans. The caps mean most options could disappear at some point before the end of the enrollment season.

"I assume there will be some additional urgency at the start," he said.

Minnesota launched the MNsure exchange in 2013 to implement the Affordable Care Act, which requires almost all Americans to have health insurance or pay a tax penalty.

The exchange is an option for the roughly 250,000 Minnesotans who purchase individual health insurance policies — health plans for people who are self-employed or don't get coverage from their employer.

Minnesotans have more incentives than ever to shop through MNsure, since premiums in the market are spiking by 50 percent or more on average. The value of tax credits should increase in tandem, meaning those who qualify won't necessarily see an increase in their out-of-pocket premium costs.

"The subsidy matters this year probably more than ever before," said Stephen Parente, a health policy expert at the University of Minnesota.

The source of the call center troubles on Tuesday is still under investigation, but O'Toole said the issues did not return on Wednesday or Thursday. During the news conference in St. Paul, she offered MNsure's first public comments on numbers released late Wednesday, which suggested the extremely high call volume was a one-day phenomenon.

Of the 80,000 total call attempts to MNsure on Tuesday, more than 5,000 of them actually were handled by call center workers, O'Toole said. The remainder of callers did not take any action, she said, beyond selecting English as their language option.

"Early on Tuesday, something seems to have happened with call volume that was unusual and suspicious," she said.

O'Toole added later: "This isn't a game. This is a really important decision for Minnesotans. ... If someone was playing a game, a lot of Minnesotans were hurt by it. And if someone was playing a game, we are committed to stop it."

Call center wait times averaged about 35 minutes on Tuesday; on Wednesday, that declined to six minutes and by Thursday morning waits averaged less than two minutes, O'Toole said.

On Tuesday, a key portion of the MNsure website was knocked down for about 30 minutes along with nearly 70 other Minnesota state government websites. Scott Peterson of the state's MN.IT department for information technology said an investigation into it continues.

Since then, the MNsure website has been stable, Peterson said.

O'Toole said health insurers still have not hit enrollment caps. The state Commerce Department approved the limits on sign-ups for four of five health insurers in the market, as an emergency measure to prevent further financial losses in the individual market.

Health plan networks are much tighter next year, as well, with less overlap across insurance companies. So, people who don't quickly sign up for a plan could be stuck with insurance that doesn't include their doctor at in-network rates.

Eagan-based Blue Cross and Blue Shield of Minnesota is discontinuing policies for about 103,000 people in the market next year, and changes in the service area for Bloomington-based HealthPartners mean about 9,100 people can't renew their coverage. While all those subscribers must shop for a new option, the enrollment limits don't create urgency for everyone in the individual market.

State law gives consumers a right to renew their current health plan coverage if the insurer is still selling the plan where they live.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck