Updated: 7:31 p.m.

House Republicans presented a four-page outline of their health care reform plan Wednesday but said they didn’t know yet how much it would cost, how they would pay for it and how many of the nearly 50 million Americans without insurance would be covered by it.

Rep. Roy Blunt (R-Mo.), who heads a GOP health task force, said that when the details are drafted in the coming weeks, they would present a plan that “costs far less than the Democrats’ [plan] and provides better results for the American people.—

But Republicans who stayed at the press conference to answer questions — the leaders made statements but didn’t stay — could not answer whether their plan would include a tax increase to pay for such costly items as refundable tax credits for low- and middle-income workers to help pay for insurance.

Other reforms proposed by the GOP were largely minor tweaks to a system that House Minority Leader John Boehner (R-Ohio) said is already the “best health care system in the world.—

“We want to work within the existing market structure,— said Rep. Joe Barton (R-Texas), ranking member on the Energy and Commerce Committee.

The Republican plan includes a proposal for association insurance pools, regional plans that cross state lines.

Republicans said they would not include a mandate that individuals buy coverage nor would they include a mandate that employers provide it, and they remained adamantly opposed to any government-run health insurance option.

Blunt said a tax on employer-provided health insurance plans was not a part of the GOP blueprint. That tax increase has been proposed by a number of prominent Republicans in recent years as part of reform plans proposed by Rep. Paul Ryan (R-Wis.), the ranking member on the Budget Committee; former President George W. Bush; and Sen. John McCain (R-Ariz.).

Rep. Dave Camp (R-Mich.), the ranking member on the Ways and Means Committee, said GOP Members are waiting for bill drafting and for a Congressional Budget Office score before they will know how much their plan will cost and how to pay for it. Camp promised that it would meet pay-as-you-go requirements, however.

Republican aides later noted that House Democrats haven’t yet said how much their bill will cost and who will be covered. And Minority Whip Eric Cantor (R-Va.) told MSNBC said that the Republican plan would use market forces to help cut costs and increase choices.

The Democratic outline released earlier this month, also four pages, did identify several ways to help pay for the plan, including by enacting a tax on employers who don’t provide health insurance and eliminating subsidies to private Medicare Advantage plans.

Democratic chairmen have also agreed to a mandate that individuals purchase insurance, and said they are also considering additional tax increases to pay for what they aim to be near-universal coverage. They also said that individuals at up to 400 percent of the poverty level would get help buying insurance.

Republicans said they would provide tax credits to low- and moderate-income Americans, but they did not specify an income level Wednesday.

Democratic aides said they are on track to release a draft of their bill by the end of the week.