People with serious pre-existing diseases, precisely those the president aimed to help with ObamaCare, could find themselves paying for expensive drug treatments with no help from the health care exchanges.

Those with expensive diseases such as lupus or multiple sclerosis face something called a "closed drug formulary."

Dr. Scott Gottlieb of the American Enterprise Institute explains,"if the medicine that you need isn't on that list, it's not covered at all. You have to pay completely out of pocket to get that medicine, and the money you spend doesn't count against your deductible, and it doesn't count against your out of pocket limits, so you're basically on your own."

The plan had claimed it would rescue those with serious pre-existing conditions.

"So it could be that a MS patient could be expected to pay $62,000 just for one medication," says Dr. Daniel Kantor, who treats MS patients and others with neurological conditions near Jacksonville, Florida. "That’s a possiblity under the new ObamaCare going on right now."

In fact, one conservative group, Americans for Prosperity, is running an ad on exactly this subject, featuring a woman with lupus, an auto-immune disease.

She starts by saying, "I voted for Barack Obama for president. I thought ObamaCare was going to be a good thing."

But Emilie Lamb says she later got a letter saying her insurance was canceled because of ObamaCare, pushing her premiums from $52 to $373 a month.

"I'm having to work a second job, to pay for ObamaCare,” she adds. “For somebody with lupus, that's not an easy thing. If I can't afford to continue to pay for ObamaCare, I don't get my medicine. I don't get to see my doctors."

One of the problems is that drugs for some diseases such as MS do not have generic versions. So without cheaper alternatives and no help from ObamaCare, patients could face huge personal out-of-pocket bills, forcing some to skimp on their medications.

Kantor worries that "this may drive more patients" to not buy their medicines, "which we know is dangerous," he says. "We know MS can be a bad disease when you’re not treating it. When you’re treating it, for most people they handle it pretty well, but we know when you don’t treat (it), it’s the kind of disease where people end up in wheel chairs potentially."

In the commercial market, of course, drugs not on a preferred list would also be more expensive, but with a major difference, according to Gottlieb.

"You go outside that list, you have to pay out of pocket for it, but you do get some co-insurance, meaning the plans will pay some of the cost of that."

Some say ObamaCare hoped to do better on that problem but ran out of time. Matthew Eyles of Avalare Health, a consulting firm, says although officials wanted "to be able to make sure that all the systems were operational in 2014, they realized that they needed to give an extra year to get those systems changes in place."

Officials intend to try again next year.

Additional benefits cost more, though, meaning premiums would have to rise, or the networks of providers would shrink even further.