States also know best how to work with community groups to reach populations that are more likely to buy off the exchanges -- the poor, the unemployed and people with limited English skills, Corlette said.

"The kind of public education campaign, the billboards and the ads and the words you use to describe this stuff, might be quite different from Alabama to Oregon or Minnesota to Texas," she said.

There are other advantages to states who decide to run their own exchanges, said Joel Ario, managing director of Mannatt Health Solutions and a former state insurance commissioner.

By running the exchanges themselves, states can coordinate regulation and enforcement of insurance plans across the commercial and exchange marketplaces.

That will likely ensure consumers are better served, particularly those who shift between private insurance and Medicaid.

But by giving the federal government control, regulation will become more complicated, making the healthcare system harder for navigate.

"That's probably in the end not as good for the consumer," he said.