The health bills passed through Senate committees would extend insurance to fewer people than the final bill passed through the House over the weekend, and Senate leaders have been refining their bill to increase that number. Hospitals and insurance companies warn that if the final Senate bill doesn't cover more people than its earlier drafts, insurance prices will increase and industry pledges to cut costs could fall apart.
The issue gets at a bigger question. President Barack Obama wants to limit the cost of a health-care overhaul to $900 billion over a decade, and the Senate bill is expected to come in around that ceiling. Nearly all the money to be spent will go toward extending insurance coverage. But how many people must be covered in order to consider that spending worthwhile?
The health bill passed by the Senate Finance Committee, which is expected to form the backbone of the final Senate bill, would extend insurance to 94% of legal U.S. residents, up from 83% of legal U.S. residents currently. The figure for those insured under the House bill is slightly higher, at 96%.
The Senate Finance bill would leave 25 million residents without insurance, with about one-third of those illegal immigrants.
"Have we really gotten the bang for the buck?" asked Mark McClellan, former Medicare and Medicaid chief under President George W. Bush. "It's a concern."
Democrats agree they want as many people as possible to get insurance. The bills expand the Medicaid health program for the poor, and provide tax credits to lower-income families to offset the cost of buying insurance. In the House bill, that benefit extends to a family of four earning $88,000 a year.
The bills also fine people who don't buy insurance and are deemed able to afford it. The penalty in the House bill is up to 2.5% of income, while Senate versions have flat penalties that, in some instances, phase in over time.
Expanding the subsidies further would bring more people into the system but drive up the cost of the bill. And there is little political support for strengthening the penalties. Democrats and Maine Sen. Olympia Snowe, the only Senate Republican to vote for a health-overhaul bill in committee, say they don't want to force people to buy a policy they can't afford.
In Massachusetts, the only state that requires residents to carry insurance, 97% of residents are insured. Hospitals and insurance companies say the federal bills should get close to that 97% level nationally.
Both industries would benefit greatly from having more customers through expanded coverage. They argue that the legislation could backfire if a larger number of people remain uninsured.
Democrats' health legislation would require insurance companies to accept all customers, regardless of their health history, and prevent them from charging customers more based on factors other than age. States such as New York and New Jersey curbed these practices but didn't require most people to get insurance, and the price of premiums rose sharply.
"We're worried that that creates a situation for people to ... only purchase health insurance when they need it," said Karen Ignagni, president of America's Health Insurance Plans, the main industry trade group. That hurts the industry because premiums paid by people who need little health care help to pay the costs of those who need a lot of care.
Hospital companies in July struck a deal with the White House under which they agreed to swallow $155 billion in lower government payments over the next decade to help fund the insurance expansion. That deal was based on getting 97% of legal residents covered by health insurance.
"The people that don't get inside the system -- if they need care -- are still going to come to hospitals," said Chip Kahn, president of the Federation of American Hospitals, who helped reach the deal. Everyone is entitled under law to treatment at emergency rooms; hospitals foot the bill for many who can't pay.
Industry groups are encouraging lawmakers to look at other ways of penalizing people who don't get insurance. Massachusetts, in the first year of its insurance mandate, denied the state's personal income-tax exemption to those who went without coverage. Insurers want Democrats to consider that tactic.
David Cutler, a professor of economics at Harvard University, attributes Massachusetts' success in getting high insurance coverage in part to shrewd branding. Getting insurance, he said, "seemed like a mainstream thing."