"The fallacy is that you can look at the pre-existing condition exclusions and turn that off, and that solves any kind of problem," said Linda Blumberg, a health economist at the Urban Institute, a Washington-based policy research group.
The Commonwealth Fund's study examined gaps in coverage when the economy was relatively prosperous. The number of people facing lapses is probably higher now, said Pamela Farley Short, a professor of health policy and administration at Pennsylvania State University.
"How many people would be helped or not helped by Romney's continuous coverage policy would depend on how long you would have had to have been continuously insured in order to qualify," Short said in an interview. Romney hasn't said how long people would have to maintain insurance under his proposal.
The Affordable Care Act that President Barack Obama championed takes a two-step approach to guaranteeing coverage for sick people.
Beginning in 2014, the law prohibits insurers from denying coverage or charging higher premiums to people who are sick and buy policies for themselves or their families. The same year, all Americans are required to have insurance unless they can show they can't afford it, under the so-called individual mandate.
The U.S. Supreme Court upheld the individual mandate as constitutional on June 28. The Obama administration and the health-insurance industry have maintained that the law's consumer protections can't function without the mandate, because people would wait until they get sick to buy coverage, a phenomenon called "adverse selection" that may contribute to higher prices and a destabilized insurance market.
"The reason the market's so dysfunctional right now, or really has failed to insure people when they need it, is largely because of this adverse selection problem," said Sara Collins, vice president for affordable health insurance at the Commonwealth Fund, which supported the 2010 health law.
As governor of Massachusetts, Romney signed into law a 2006 health overhaul that required most state residents to carry insurance. People who don't receive coverage at work can buy policies, even with a pre-existing condition, through a state- run marketplace that the Obama administration has said was a model for the exchanges in the federal law. Romney has distanced himself from the state law since starting his campaign for president and has said he would roll back the U.S. law.
Wrong Impression • "Governor Romney has made clear repeatedly that he will repeal Obamacare in its entirety and replace it with patient- centered reforms that protect Americans' access to care," a campaign spokeswoman, Andrea Saul, said in an e-mail.
Romney's "Meet the Press" comments raised questions about the details of his health-care policies going forward.
"There are a number of things that I like in health-care reform that I'm going to put in place," Romney said in the NBC interview. "One is to make sure that those with pre-existing conditions can get coverage."
The show's host, David Gregory, didn't ask Romney to elaborate on that statement, leaving the impression that the candidate had endorsed a major provision of Obama's health law. Romney's comments weren't intended as new policy, Saul said.
Any replacement of the Affordable Care Act will ensure "that people who have a pre-existing condition who've been insured in the past are able to get insurance in the future so they don't have to worry about that condition keeping them from getting the kind of health care they deserve," Romney said in a June 12 speech.
The 1996 HIPAA law, the Health Insurance Portability and Accountability Act, affords some protections to people who leave a job with health insurance. Exiting workers with at least 18 months of continuous coverage must first enroll in a program called Cobra, which temporarily extends employer-sponsored benefits for workers who lose their jobs as long as they pay for the premiums themselves.
Once they exhaust their Cobra benefits, usually after 18 months, workers are guaranteed the opportunity to purchase a health plan that covers pre-existing conditions, Blumberg said. Federal law is silent on how much that policy can cost.
"It does give some protections in terms of continuous coverage, better than what was before, but there's no guarantee that it's affordable," Blumberg said.
Existing Law •Romney's policy isn't substantially different than existing law, said Lis Smith, a spokeswoman for the Obama campaign.
"If he wanted to show leadership, he would stand up to insurance companies, make tough, often politically unpopular choices like the president did and stop all discrimination for people with pre-existing conditions not just for those with coverage, but for all 129 million Americans who have a pre- existing condition," she said in an e-mail.
Smith's figure is an Obama administration estimate of the number of people with pre-existing conditions. Families USA, a Washington consumer advocacy group that supports the health law, reported a more conservative estimate, about 65 million, in July.
HIPAA's guarantee of protections against pre-existing condition exclusions "didn't really pan out very well," said James Capretta, a health policy researcher at the Ethics and Public Policy Center who said he supports Romney and occasionally advises the campaign. Capretta said he would rather see a blanket rule letting people move seamlessly from employer- provided plans into policies they buy for themselves.
"Paying the full expense of Cobra coverage is a bit daunting," he said. "A lot of people aren't even aware that's a requirement to retain this protection. So they end up not doing it."