People seeking health insurance via MNsure outside the standard open enrollment period will now be required to document their eligibility for "special enrollment" before they can buy a policy.
MNsure said the tighter rules should help make sure people don't wait until they are sick to buy coverage, a practice that drives up costs for others.
The change follows concerns among insurers about potential "gaming" in the state's market where individuals buy coverage.
"This follows what the federal government is already doing, and what many other states are, as well," said Jeremy Drucker, a MNsure spokesman. He added in an e-mail: "If it slows down the process at all, it would be by days."
MNsure is an option for the roughly 170,000 Minnesotans who buy individual policies, a group made up primarily of those under age 65 who are self-employed or don't get health insurance from their employers.
Most who buy coverage through MNsure do so during an open enrollment period that typically stretches between November and January. The exchange allows for enrollment at other times in special circumstances such as the birth of a baby, marriage, a move to a new area or the loss of other health coverage.
Previously, MNsure let individuals enroll in coverage if they attested to eligibility for special enrollment, and then supplied required verification within 35 days. About 14,000 people last year bought insurance through MNsure during a special enrollment period.
In response to concerns about special enrollment abuse, MNsure last year initiated a study that looked at special enrollments for roughly 1,500 people across some 1,000 households between February and April. The study found that 24 percent of households did not provide sufficient documentation.