We all know people have signed up for insurance through the healthcare exchanges, or enrolled in Medicaid.

But a new report in the New England Journal of Medicine shows about five million people bought coverage straight from an insurance company.

There’s nothing new about people buying insurance policies directly from insurers; it’s been happening forever.

But Harvard’s Ben Sommers says not for everybody.

“It’s a good market if you’re healthy, but if you have pre-existing conditions, you either faced really high premiums or were denied coverage,” he says.

The Affordable Care Act blocks insurers from doing that anymore. Plus, the ACA requires most everyone to have insurance.

Because of all that, Sommers estimates 20 percent of the people who bought directly from companies are newly insured.

It could be the start of a dominant trend.

“As the marketplace matures, it will be folks with higher incomes that won’t be subsidy eligible that will be buying insurance in the future,” says Paula Sunshine with Independence Blue Cross in Philadelphia.

She says her company has invested heavily to make it as easy as possible for consumers to buy policies.

Ultimately, Sunshine says her industry will grow as employers stop buying coverage for their workers, and workers start shopping for their own insurance.