Kirsten Johansen was puzzled when she went to cast her ballot on the first day of early voting and was told by an election worker that her registration had been challenged.

"I was shocked," said Johansen, an Edina resident, who hasn't moved and recently cast a ballot in the May special election for Hennepin County commissioner. She figured double-checking her registration for the general election was unnecessary.

"I thought, of course I'm registered, I just voted a couple of months ago," she said. "I got there and the woman said, 'Sorry, it appears you're a challenged voter.'"

Johansen said she doesn't know why her registration was challenged. It didn't happen to two other members of her household.

Johansen is among a small group whose voter registrations are challenged each year because of a discrepancy in data the state collects and analyzes to ensure the voter rolls are accurate. Big jumps in registrations around important elections can lead to more challenged voters.

Minnesota election officials routinely compare voter registrations with data they receive from other state and federal databases such as Driver and Vehicle Services, the Social Security Administration, the Department of Health and court records, said Secretary of State Steve Simon.

Typically, a registration is challenged because a postal verification card sent to a voter's home is returned as undeliverable. But it can also happen if someone doesn't vote for four years, they move, show up registered somewhere else, the courts deem them ineligible for some reason or for other less common reasons.

"Challenged status is a constant churn," Simon said. "They are either removed or added, depending on the information that we get."

As of Oct. 14, Minnesota had nearly 3.7 million registered voters and 55,072 of them had a challenged registration — about 1.5%, according to Simon. That's typical of past elections and similar to the percentages of challenged registrations in other states.

Voters shouldn't be dismayed if they end up on the challenged list.

"This is a security feature," Simon said. "It doesn't mean the person is purged. It doesn't mean they can't vote. It means, if and when they attempt to vote, they have to show more to overcome the challenge."

Fixing the challenge

Doing that is typically as simple as registering to vote.

"It means you have to show both — you are who you say you are and you live where you say you live," Simon explained.

That could mean showing an ID, or a utility bill or even having a neighbor vouch for you. When registering, Minnesota voters sign a form acknowledging it is a felony to provide false information.

Johansen ended up filling out a new voter registration form before casting her ballot during early voting in Edina.

"Fortunately, I had ID with me," Johansen said, urging other voters to check their registration status. "My advice is don't blow it off. Listen to them when they say check if you are registered."

With a few exceptions, anyone who is a U.S. citizen, is at least 18 years old and has lived in Minnesota for 20 days immediately before Election Day is eligible to vote. Exceptions include someone under a court-ordered guardianship in which the right to vote has been revoked, or a person determined by a court to be legally incompetent to vote. People can't vote while incarcerated for a felony. Under a new law, once they are released, they are eligible to vote.

New automatic voter registration

Election officials note that the routine checks they do of existing voter registrations is different from the intensified document review process tied to the automatic voter registration system launched earlier this year. That system registers eligible voters when they get a state ID or driver's licenses.

State officials noted that only residents who provide the proof of citizenship required for a REAL or enhanced ID would be automatically registered. In September, election officials said about 1% of the 100,000 automatic registrations were inactivated because they needed further review.

Voters can easily check their registration on the Secretary of State's website. Providing a name, date of birth and address will verify registration status and give a polling location for the upcoming election.

Voters can update a challenged registration before Nov. 5 at their local elections office. Or they can bring the needed documentation to the polls on Election Day.

Beginning Friday, residents can fill out their ballots at early voting locations and feed them into a tabulator rather than casting an absentee ballot. As of Thursday, the Secretary of State's Office sent out more than 716,000 absentee ballots and has accepted 337,633 ballots.

Voters can check the status of their absentee ballot on the Secretary of State's website.