Should Medicare cover the new generation of anti-obesity drugs? If it should, at what price? These are key questions in the debate over the new anti-obesity drugs. Their results are remarkable. But under a rule established in 2003, Medicare is prohibited from covering weight-loss medications.

Given that these drugs work so well for middle-aged adults, older Americans should have access to them as well: That is the premise of the Treat and Reduce Obesity Act, which would allow Medicare to cover weight-loss drugs. Introduced by Senators Tom Carper (D., Del.) and Bill Cassidy (R., La.), the bill awaits committee action. Cassidy, a former liver specialist, has firsthand experience treating advanced obesity.

The new drugs, GLP-1s (glucagon-like peptide-1s), target a hormone receptor in the gut and brain, slowing digestion and, through mechanisms still not fully understood, reducing appetite. Diabetics have used lower-dose and shorter-acting GLP-1s for over a decade. The drugs have recently been reformulated for weight loss through higher doses and weekly shots. These latest drugs — Wegovy from Novo Nordisk and Zepbound from Eli Lilly — yield 15 to 20 percent weight loss in the average patient. Next-generation drugs targeting multiple hormone receptors are now in clinical trials. Early data suggest they could reduce weight by 25 to 30 percent, levels that until now had been possible only through surgery.

The even better news is that the drugs do more than reduce weight. They counteract a range of conditions, including diabetes and liver, heart, and kidney diseases. The drugs may even help postpone Alzheimer’s disease; a clinical trial later this year should tell us more.

The bad news is that people need to stay on the drugs to maintain their reduced weight. Those who stop tend to regain half or more of the weight they lost. Taking drugs for decades is not necessarily a problem. Millions of Americans take blood-pressure or anti-cholesterol pills for many consecutive years. GLP-1s act in multiple organs and have systemic effects, however. Decades of use may lead to unanticipated problems. And, as with any powerful drug, a small percentage of people who have tried GLP-1s have had to stop because of serious side effects.

On balance, for most adults with obesity, the advantages outweigh the disadvantages. This is important, as obesity prevalence among Americans surpasses 40 percent, with diagnosed diabetes exceeding 10 percent in most states. Americans with obesity and related conditions have an average life spans that is five to ten years shorter. Stopping or slowing chronic disease through weight-loss drugs could also add years of productive living for tens of millions of Americans.

Which brings us back to Medicare. Its annual cost is now over a trillion dollars, the vast bulk of it spent treating chronic disease. These costs land on Medicare because the worst aspects of chronic disease take years to develop. Drugs to manage blood sugar or blood pressure blunt symptoms in midlife, but underlying disease still progresses. By 65, people with metabolic syndrome — including obesity, diabetes, and heart and liver disease — are on a sure path to disability, hospital trips, loss of vision and mobility, and huge bills.

You see this in how lopsided Medicare spending is. The 30 percent of beneficiaries who have multiple chronic conditions account for 70 percent of Medicare costs. Just 2 percent of beneficiaries have the most advanced form of metabolic syndrome, a trifecta of diabetes, heart failure, and chronic kidney disease, and yet they account for 7 percent of Medicare spending. Beneficiaries with all three conditions cost Medicare $45,000 a year on average, 4.5 times as much as beneficiaries who have none of them.

The situation will get worse before it gets better. Americans entering Medicare in the next two decades have higher rates of metabolic disease than current recipients had in their fifties and early sixties. Medicare’s incremental costs to treat more-severe chronic disease longer could total half a trillion dollars over the next decade. We must act quickly to stop or reverse the rising incidence of metabolic syndrome.

If we do act quickly, the economic and societal benefits could be immense. Preventing chronic disease means that people would be healthier longer, live longer, spend less of their savings on health care, and do not have to rely on partners to care for them. Broad access to obesity drugs could save as much as $100 billion a year, in reduced Medicare spending plus economic benefits from living longer and spending retirement savings on more-productive areas, according to a study by the Schaeffer Center for Health Policy at the University of Southern California.

Obesity drugs would be an immensely important tool in that effort. GLP-1s appear to work as well in older Americans as in younger people, although the pace of weight loss for older people is slower. The key issue is to ensure that as older people shed pounds, they maintain muscle mass and bone density.

How much should Medicare pay for them? The current prices being discussed for private insurers are not much help. There is a complicated dance going on between GLP-1 drugmakers, which are trying to maximize their profits, and insurers, which are trying to minimize costs. The list prices for Wegovy and Zepbound range from $800 to $1,200 a month, but drug pricing is like furniture-shopping: No one pays list price. Last fall Eli Lilly, the maker of Zepbound, announced that it would accept $550 a month from Americans who are not covered under their health plans.

Even at that price, broad Medicare coverage would be a challenge. There are at least 10 million people over 65 who are certain to qualify for obesity drugs. Supplying all of them for a year would bump up annual Medicare spending on drugs by about $50 billion. There would be massive societal benefits, but they would be realized elsewhere, outside of Medicare’s fiscal window.

Some commentators have therefore concluded that the drugs are just too expensive for Medicare to cover; perhaps they can be included in a few years as generics. But it would be a terrible mistake to wait for years as a massive disease burden builds up.

A much better option is to push drug companies to develop a different pricing structure for Medicare, one that affords broad access to seniors without breaking the bank. Instead of paying per dose, the government would give a minimum-dollar commitment to pharma companies and make additional purchases, if necessary, at a deeply discounted price. Above a total dollar spend, incremental doses would be free.

To illustrate: Medicare and drugmakers might set a minimum annual purchase commitment of $5 billion, for up to 3.3 million beneficiaries. That’s about $1,500 per person per year. That’s the price that Medicare would pay for any additional people covered, up to a total cost of $10 billion, or about 6.7 million Medicare beneficiaries. For beneficiaries above that level, Medicare would pay drug companies nothing.

At first glance, you might think: That’s crazy, why would a pharma company agree to that? But a few pharma companies already took a deal similar to this a few years ago when they wanted to broadly distribute a new but expensive treatment for hepatitis C. This approach also builds on the Trump administration’s approach in Operation Warp Speed to ensure supply by committing to buy millions of doses.

Drugmakers would benefit by securing revenue and reducing risk. Makers of GLP-1s are scrambling to build factories but face a lot of uncertainty about how much of their drug they will sell. That’s because private insurers resist newer drugs in favor of older, cheaper ones. A minimum-purchase agreement with Medicare would take much of that risk away. Drugmakers also have a lot of uncertainty about how long someone will stay on a drug. Drugmakers spend a lot on discounts and other marketing to encourage patients to continue treatment. Under a minimum-price commitment, that risk shifts to Medicare.

For Medicare, the main benefit is a vastly better average price per person, with potential massive upsides in the form of better health outcomes and their associated savings in treatment costs. Taxpayers would benefit as millions of Medicare recipients would live longer without developing advanced chronic disease. We would get valuable information quickly about how these drugs work for older Americans, insights from which could help us refine how the drugs are used by middle-aged Americans.

A lot of good would come from having Medicare cover obesity drugs, starting with passage of the Treat and Reduce Obesity Act, with guidance to Medicare to develop an innovative pricing scheme. The alternative of leaving obesity untreated among older Americans is far worse, and the consequence, chronic-disease spiral, would be virtually certain. With a little imagination, however, we can make these drugs available at a price that allows millions of older Americans to benefit from them, creating net value and savings for taxpayers.