Like Obama's law, GOP's health plan relies on young, healthy people to buy in

Some big insurance companies left the marketplace because they didn't want to take on that risk.

Under the Affordable Care Act, which is also called Obamacare, Americans who did not buy insurance had to pay a penalty in an attempt to balance out the risk pool. The GOP's American Health Care Act eliminates that penalty but institutes a one-time 30 percent surcharge for people who go more than two months without insurance.

Dr. Jonathan Oberlander, a professor of social medicine at the University of North Carolina at Chapel Hill's Medical School, said the surcharge might not be enough to cover the difference.

"Is that going to be an adequate substitute for Obamacare's individual mandate penalty?" Oberlander said. "We've already said that penalty isn't strong enough to induce as many young, healthy people to sign up.

"This penalty is potentially even weaker because it's not something that you pay every year. You only pay it when you choose to get health insurance."

The difference, then, would rely on enough young and healthy people to sign up for insurance. Oberlander said if those people don't sign up, more insurers could abandon the marketplace.

If insurers bail on the marketplace, there could be more of what's happened in North Carolina: Blue Cross Blue Shield left the market and have a monopoly on the marketplace here and is able to raise premiums.

Blue Cross Blue Shield has already said it does not support the GOP's new bill.