More than 4,000 vehicle registrations have been suspended this year, compared to 431 in all of 2011, Ruth Johnson said.
"I'm surprised at the numbers. We're seeing very elaborate scams to take advantage of people," Johnson said in an interview. "If you get into an accident it can alter your life if you don't have insurance and you think you do."
Proof of no-fault insurance is required to register more than 7 million passenger vehicles in Michigan each year. Insurers are required to send electronic verification to the state, but many motorists still can present paper certificates at secretary of state offices. That's where fraud has been discovered.
On July 31, more than 16 percent of 3,500 paper certificates were invalid or phony, Johnson's office said.
Johnson said phony insurance affects every motorist because rates can go up to compensate for the injuries of uninsured drivers and passengers.
"It's an economic burden on the honest people," she said.
Some fake certificates had a computer code that read, "Llamas are sooo cool," when scanned. Johnson said some scammers have set up "help desks" to answer the phone and verify insurance if the state calls.
"We had fakes or forged copies turn up in more than half of Michigan's 83 counties," Johnson said.
At the same news conference, Eaton County Prosecutor Douglas Lloyd announced charges against a Detroit-area man accused of advertising fake insurance on Craigslist. The ad carried the line, "use at your own risk. ... No refunds."
The secretary of state's office will be part of a task force that'll investigate ways to reduce insurance fraud. The group will include state police, prosecutors and insurance trade groups.