WASHINGTON — Conservative health care scholars are praising Mayor Giuliani’s sketch of a proposal to transition away from an employer-based health insurance system toward one where more individuals own their policies.

Mr. Giuliani is planning to issue a more detailed policy proposal this summer, but his early message signals that he will try to outflank a chief Republican rival, Mitt Romney, on the issue. As governor of Massachusetts, Mr. Romney signed into law a plan that requires every state resident to purchase health insurance.

Some economic conservatives have criticized the law as an expansion of government regulation, but others praise Mr. Romney for achieving, in a famously Democratic state, an agreement that could result in a dramatic increase in the number of insured people without resorting to a tax increase.

Mr. Giuliani’s proposal does not include a mandate, a facet he will likely use to appeal to conservatives who are wary of the Massachusetts law.

The former New York mayor routinely refers to efforts by Democratic candidates to enact universal health care as a path to “socialized medicine.” He offered the outline of his own plan, which includes health savings accounts and tax deductions of $15,000 to families, at the GOP debate Tuesday night, and he elaborated on it in an article in the Wall Street Journal yesterday.

“What I would do is change the whole model for health insurance in this country,” he said during the debate. “The problem with our health insurance is it’s government- and employer-dominated. People don’t make individual choices. It’s your health — you should own your health insurance.”

Health policy experts viewed Mr. Giuliani’s proposal as an extension of one advanced by President Bush earlier this year, which sought to make health insurance more affordable by changing the tax code to give breaks to people who buy private insurance. A health economist at the American Enterprise Institute, Thomas Miller, praised Mr. Giuliani’s approach and called it a “second-stage evolution” of the Bush plan, but he cautioned that Mr. Giuliani’s vision for transforming the health insurance market was easier said than done.

“That’s a little premature,” Mr. Miller said of an effort to make individually-owned coverage the centerpiece of a new system. The goal, he said, should be to boost the individual market so it can compete fairly with group plans offered through employers.

The Democratic National Committee was also quick to note the similarity to the Bush plan.

“Instead of confronting skyrocketing health care costs, Giuliani is recycling President Bush’s failed agenda and finding new ways to auction off our health care policy to the highest bidder,” a spokesman for the DNC, Damien LaVera, said.

A third leading Republican candidate, Senator McCain of Arizona, has not offered a specific health care proposal, but like Mr. Giuliani, he opposes an individual mandate.

Mr. Romney advocates the law he negotiated in Massachusetts as a model for other states, but he has indicated he does not intend to propose a similar plan on the federal level.

Instead, he would encourage states to develop plans on their own and use the federal government to give them the flexibility to do so. His defense of the Massachusetts plan on Tuesday night was straightforward.

“I’m the guy who actually tackled this issue,” he said during the debate. “We get all of our citizens insured. We get people that were uninsured with private health insurance. We have to stand up and say the market works. Personal responsibility works.”

Mr. Romney at the debate made no mention of the insurance mandate, which was not part of his initial plan in Massachusetts. Rather, he proposed allowing residents the choice of putting up a $10,000 bond that could cover their costs if they needed emergency care.

The director of the Center for Health Policy Studies at the Heritage Foundation, Robert Moffit, who worked on the Massachusetts effort, said Mr. Romney made substantial progress in lowering costs and increasing choices for consumers, including making insurance portable between jobs. “The political achievement was enormous,” Mr. Moffit said.

Negotiating in a political culture dominated by Democrats, Mr. Romney could only go so far, he said. “If the argument is that he didn’t persuade the liberal Democratic legislature to be more conservative, then they’re correct,” Mr. Moffit said.

Mr. Giuliani’s proposal and his appeal for “individual choice” resonated in particular with critics of the Massachusetts law. “The Giuliani plan is infinitely superior,” the director of health and welfare studies at the Cato Institute, Michael Tanner, said. “They’re not even in the same league.”

Mr. Tanner derided the law Mr. Romney signed as an “unprecedented infringement on individual liberty.”

During the debate, Mr. Giuliani compared his idea for health insurance to the current model for car insurance or homeowners insurance, where people don’t have to be covered for minor accidents or repairs and have more choice in what they can pay for themselves. Conservative health policy scholars agreed with the push for more choice, but several said they are waiting to hear more from the former mayor. “In broad outline, it’s certainly encouraging, but there’s a lot of detail left to be filled in,” a former policy adviser to President Bush who is now at the Center for Medicine in the Public Interest, Douglas Badger, said.