Oct. 16, 2012 -- Just in time for tonight's presidential debate, the Kaiser Family Foundation has released a new study that shows six out of 10 Medicare beneficiaries would pay higher premiums under a hypothetical new plan similar to what Republican presidential challenger Mitt Romney has proposed.

Kaiser researchers used elements of the Ryan-Wyden Medicare overhaul proposal (which Romney has endorsed) and the Domenici-Rivlin plan to build their hypothetical plan, which caps federal contributions based on plan costs in a geographic area, and requires individual beneficiaries to pay the difference. When researchers applied 2010 data, they found major differences in premium costs across the nation.

"While all beneficiaries would have a choice of a low-cost plan, some would pay more -- and perhaps considerably more -- to be in either a traditional Medicare program or a private plan that they might prefer, and that's a big change from Medicare as it's known today," Tricia Neuman, Kaiser's top Medicare expert, told ABCNews.com.

For example, in battleground state Florida, 77 percent of Medicare beneficiaries would pay an additional $100 or more in monthly premiums under their current health plans, according to the study. On the other end of the spectrum, no one in Alaska would pay an additional $100 or more on their monthly premiums. The rest of the states fall somewhere in between.

Neuman and her team used 2010 dollars in their analysis instead of 2022 dollars, as analysts at the Congressional Budget Office used for their review of vice presidential candidate Paul Ryan's original proposal, which excluded a traditional Medicare option. The current dollars reflect that researchers used real data and bring the findings into the present even though most of the plans wouldn't take effect until sometime in the future.

"We thought it would be helpful to illustrate the effects using actual data rather than produce a report with lots and lots of assumptions of what could change between now and 2022," Neuman said.

Kaiser researchers don't typically comment on whether their studies prove plans are good or bad, but the Obama campaign has already picked it up as a weapon against the Romney-Ryan ticket, calling their plan "irresponsible."

"It's long been clear that Mitt Romney's plan to turn Medicare into a voucher program would have devastating consequences," a BarackObama.com post on the study reads. "Romney and Paul Ryan like to claim that seniors would always have the choice of enrolling in traditional Medicare, but a new study demonstrates just how hollow that claim is."

Romney campaign officials have already fired back that Kaiser was not looking at Romney's plan, or any specific plan.

"As the authors stress, this is not a study of the Romney-Ryan plan," campaign spokesman Andrea Saul emailed the National Review. "Our plan would always provide future beneficiaries guaranteed coverage options with no increase in out-of-pocket costs from today's Medicare."

Kaiser's hypothetical plan assumes that health-care premiums for seniors is based on the second-lowest private insurance plan in a county or traditional Medicare, whichever is less expensive, just as the Romney-Ryan plan proposes.

If an individual beneficiary's plan goes over that dollar value, he or she has to pay the difference. The Romney-Ryan plan does not say on which geographic area (state, county, etc.) the caps and payments would depend.