That left just 4.9 percent of all Minnesotans lacking health coverage on May 1, about a month after the federal health law’s first major sign-up deadline. That’s down from 8.9 percent last Sept. 30.

“A change in the uninsurance rate like this is pretty much unprecedented in Minnesota,” said Julie Sonier of the university’s State Health Access Data Assistance Center and a co-author of the report. […]

“People haven’t enrolled in such large numbers before in such a short period of time, so there was something else going on during the open enrollment period,” Sonier said. “Whether it was awareness of the individual mandate or far more intensive, effective outreach ... something really got these people in the door where other attempts to do so had not been successful.”