The Senate bill, which passed 60-39 on Christmas Eve with no Republican backing, has drawn tentative support from some large corporations and industry groups, despite containing a range of provisions that they hope to change. By contrast, businesses of all sizes oppose the House bill, which contains more-stringent requirements on employers to offer health coverage to employees.
Leaders of the two chambers of Congress plan to meet in January with the aim of cobbling together a final health-care bill. Both the Senate and House would need to pass that final version, before it goes to President Barack Obama for his signature.
The support of business leaders isn't critical for passage, but it could help Democrats blunt Republican criticism that their bill is bad for the economy.
Many of the country's biggest employers have raised alarms over a provision in the Senate bill that would tax a government subsidy on retiree drug benefits. The move could force an accounting step that would require hundreds of companies to sharply lower their earnings next year.
Big businesses also worry that new taxes and fees proposed in both versions of the health legislation could come years before measures meant to contain wasteful spending in the delivery of health care by doctors and hospitals take effect.
"It is the mismatch of the timing that we don't like," said John Castellani, head of the Business Roundtable, which represents major corporations. "The final bill needs to accelerate the delivery-system reforms, and to get rid of the mismatch in new taxes and fees, and the arrival of the measures that will lower costs."
Groups representing smaller and medium-sized firms have largely denounced the overall effort, saying it would drive up their costs. The Senate bill "implements crippling new taxes, and hurts our ability to create jobs at the worst possible time for the economy," said U.S. Chamber of Commerce Executive Vice President Bruce Josten.
Democrats argue that the final result will drive down health-care costs for the self-insured and for small businesses. They say the new taxes in the Senate bill would target drug companies, health insurers and others in the health-care system, and that a proposed tax on high-value or "Cadillac" health plans could reduce costs by discouraging overly generous insurance plans.
White House spokesman Robert Gibbs on Sunday said negotiations over the final bill would focus on how to control health-care costs, in part by targeting insurance companies that provide plans that are "far too generous."
"The best way to bend that cost curve is to go after and work on eliminating excessive Cadillac plans that people at Goldman Sachs and big bankers might get," he said on NBC's "Meet the Press."
"That's what the focus will be in this. I think the president believes that we can work out a solution."
On Sunday, Sen. Robert Menendez (D., N.J.), speaking on "Fox News Sunday," said the final bill "will look very much like the Senate version."
Rep. Chris Van Hollen, a Maryland Democrat appearing on the same program, said House lawmakers are "not going to rubber-stamp the Senate bill. On the other hand, we recognize the realities in the Senate," where the bill passed with the bare minimum of votes needed to overcome any Republican efforts to block it.
The Senate bill doesn't contain a government-run health-insurance plan, or public option, which is part of the House bill. Mr. Van Hollen said that if House members give up the public option, they want to make sure that the private insurance plans aren't too pricey. "We're asking everybody to have health insurance," he said. "It's got to be affordable."
Sen. Jim DeMint (R., S.C.) said on "Fox News Sunday" that it wasn't too late for Republicans to kill the health-care overhaul. Democrats "want 80 to 90% of Americans on government health care," he said. "That's not a good thing for our country."