Republican critics have a fiercely argued list of reasons to oppose health care reform. One that is resonating is that the nation cannot afford in tough economic times to add a new trillion-dollar health care entitlement.

We understand why Americans may be skittish, but the argument is at best disingenuous and at worst a flat misrepresentation. Over the next two decades, the pending bills would actually reduce deficits by a small amount and reforms in how medical care is delivered and paid for — begun now on a small scale — could significantly reduce future deficits. Here is a closer look at the benefits and costs of health care reform:

STATUS QUO IS UNSUSTAINABLE More than 46 million Americans have no insurance, and millions more have such poor coverage that a severe illness threatens bankruptcy. Small employers are dropping coverage because of the cost. Those lucky enough to have insurance are struggling with higher premiums and co-payments, and worry that if they are laid off they could lose coverage.

Without reform, that bad situation will only get worse. The Commonwealth Fund, a respected research organization, warned that the average premium for family coverage in employer-sponsored policies would almost double in the coming decade, from about $12,300 in 2008 to $23,800 in 2020, with part paid by workers and part by employers. Premiums are also soaring for individuals who buy their own coverage directly.

BUT A TRILLION DOLLARS? Both the House and Senate bills would cover more than 30 million of the uninsured, and fully pay for it — in part by raising taxes (either on wealthy Americans or high-premium health plans and certain manufacturers and insurers) and in part by cutting payments to health care providers and private plans that serve Medicare patients.

A trillion dollars is still a lot of money, but it needs to be put in some perspective. Extending Bush-era tax cuts for the wealthy would very likely cost $4 trillion over the next decade. And the Medicare prescription drug benefit, passed by a Republican-dominated Congress, is expected to cost at least $700 billion over the next decade. Unlike this health care reform, it became law with no offsetting cuts and very little provision to pay for it.

YES, THEY OVER-PROMISED President Obama and his aides have, at times, made it sound as if health care reform was the answer to runaway deficits and soaring premiums. That is true in the long run, but not now.

The Congressional Budget Office projects that the vast majority of Americans, those covered by employer-sponsored insurance, would see little change or a modest decline in their average premiums under the Senate bill. It predicts that the bills would reduce deficits in the first decade by a modest $130 billion or so and perhaps $650 billion in the next decade — a small share of the burden.

Critics scoff that Congress will never carry out the required cuts in payments to Medicare providers. It is true that Congress has repeatedly deferred draconian cuts in doctors’ reimbursements. It has had no reluctance imposing other savings. The Center on Budget and Policy Priorities, a liberal analytical group, examined every major Medicare cut in deficit reduction bills over the past two decades. Virtually all of the savings imposed in the 1990, 1993 and 2005 bills survived intact. So did 80 percent of the savings in the 1997 Balanced Budget Act.

There is an easy way to stiffen Congress’s spine: it should adopt separate pay-as-you-go rules that would require that any concession to providers be paid for by tax increases or compensating cuts in other programs.

SHOULD WE GIVE UP ON SAVINGS? The House and Senate bills, and the stimulus legislation, have a lot of ideas that could bring down costs over time.

Electronic medical records could eliminate redundant tests; standardized forms and automated claims processing could save hundreds of billions of dollars; “effectiveness” research would help doctors avoid costly treatments that don’t work; various pilot projects devised to foster better coordination of care and a shift away from fee-for-service toward fixed payments for a year’s worth of a patient’s care all show some promise.

These reforms are mostly untested. And the C.B.O. is properly cautious when it says that it does not see much if any savings for the government during the next decade, in part because of upfront costs and in part because no one knows what will work. These efforts are unlikely to be tried on any serious scale without reform.

NO SINGLE FIX The debate is not over and sensible proposals are emerging in the Senate to strengthen cost control. Various amendments would increase the penalties for hospitals that infect patients, let Americans import cheaper drugs from abroad and modestly increase the powers of a new commission that is supposed to recommend ways to reduce Medicare costs. The House bill has cost-cutting measures that could be incorporated into a final bill, including authority for the government to negotiate lower drug prices for Medicare beneficiaries.

Aggressive testing of promising ideas should increase the likelihood of ultimate success. And millions of uninsured Americans should not be forced to wait until all the answers are found.