ST. PAUL — MNsure tapped its interim leader Wednesday to run the health insurance exchange permanently even though she didn’t apply for the job.

The health insurance exchange’s board selected Allison O’Toole to remain at the helm. She was chosen over health care consultant Mark Nyquist, who was named the sole finalist for the position earlier this month.

The board added O’Toole as a second finalist shortly before moving into a private meeting to vote on who would fill the position. O’Toole had been MNsure’s acting head since May, when the former CEO stepped down for another job. O’Toole hadn’t applied for the position.

Board chair Peter Benner defended the reversal and tapping an insider who hadn’t applied for the job as legal, transparent and prudent. He said they were not required to reopen applications to consider O’Toole.

“As a board, we would not be responsible to the organization and to the citizens to exclude somebody who we thought was very qualified to do the job,” Benner said.

In the midst of the exchange’s third open enrollment period, a new executive’s ability to “hit the ground running on day one” weighed on Benner’s mind. So did the high turnover: A new leader would have been MNsure’s fourth in less than three years.

Benner said he asked O’Toole to reconsider late last week, pegging her as the best fit for the job.

In a written statement, O’Toole said she looks forward to building on progress made over the past six months, including the introduction of a cost comparison tool for people shopping for new plans.

“After recent conversations with the board and giving it fresh consideration, I realized my work at MNsure isn’t done yet,” she said. “I’m honored by the board’s trust. I’m empowered by this incredible team and I’m looking forward to continuing to lead MNsure into the future.”

Forty-two candidates applied for the top job. The board interviewed 11 candidates and eventually forwarded the name of Nyquist, a health care consultant and former executive at UnitedHealth. He didn’t respond to an email seeking comment.

Prior to taking the lead role, O’Toole was formerly the exchange’s deputy director for external affairs. She was previously state director for U.S. Sen. Amy Klobuchar, a director at a Twin Cities public affairs firm and a former prosecutor for two large counties. She has a law degree and a bachelor’s degree in government.

State Sen. Michelle Benson, a Republican who has closely tracked MNsure, credited O’Toole for her tenure at MNsure but said the board’s selection process prompted larger questions.

“Just because something is ‘legal’ doesn’t mean it’s the best way to handle a situation,” she said. “I think the board should make an extra effort to be more straightforward and transparent. They didn’t do that today.”