One advertisement on Facebook promises zero-cost dental care for elderly Americans hit hard by rising medical bills. Another, on Instagram, offers free groceries in exchange for an email and phone number.

But the ads are misleading, at best.

So bad is the problem of deceptive Medicare marketing that a US congressional committee has asked 15 states to investigate. Big insurance companies, worried about their reputations and potential fines, have started to take note.

"If there's money to be made in finding customers for a particular product or service, chances are there will be a firm trying to get people to click on links on Facebook," said John Breyault, an expert on fraud and scams at the National Consumers League.

Between 2020 and 2021, complaints from the tens of millions of Americans aged 65 and older who qualify for federal health insurance more than doubled, according to the Centers for Medicare and Medicaid Services (CMS).

Many complaints mention firms that hawk Medicare Advantage plans, which are provided by private companies.

The online offers examined by AFP allude to genuine benefits in some of those plans. "Flex cards," for example, are offered to some chronically ill beneficiaries to help pay for out-of-pocket expenses.

"With inflation taking a bigger bite out of people's pocketbooks for things like groceries and gas and other day-to-day expenses, an ad promising you help with that could be particularly enticing," Breyault said.

Claims of free dental care and grocery cards have circulated widely on social media since January 2022, when enrollment for Medicare Advantage began.

But the benefits are only available to a comparatively small audience. And as older, typically unwaged citizens are hit by rising prices, watchdogs say they could be misled into changing their plans during traditional Medicare enrollment in October.

- 'Money at stake' -

Over the past nine months, dozens of Facebook pages have promoted free grocery cards and dental care in hundreds of English- and Spanish-language posts -- some of which were boosted as ads and later removed for violating platform policies, an AFP analysis shows.

One Facebook page called Senior Savings Club promoted a webpage promising a "spending card for free groceries" in dozens of posts, according to the Facebook Ad Library, a public archive of paid advertisements on Meta platforms.

The site's terms and conditions link to another website owned by Assurance IQ, a subsidiary of US insurance firm Prudential Financial. Bill Launder, a spokesperson for the Fortune 500 company, said a marketing firm created the video ad.

"Prudential, through its business unit Assurance IQ, terminated that affiliate marketing relationship due to concerns about misleading marketing practices," he told AFP.

Other marketing companies also appear to be publishing Facebook ads and posts laced with misleading claims.

A Facebook account sharing a webpage that advertises "no-cost vision and dental benefits" -- which Medicare does not usually provide -- is run by WeCall Media. The North Carolina company says on its website that it generates leads for clients such as Assurance and State Farm, another insurance firm.

David Lipschutz, associate director of the Center for Medicare Advocacy, said there are "very heavy incentives" for companies to push Medicare Advantage plans over other kinds of federal health insurance because agents can make more commission.

"There's a lot of money to be made and a lot of money at stake," he said.

AFP contacted WeCall for comment, but no response was forthcoming.

- 'Do your research' -

In comments on dozens of posts reviewed by AFP, Facebook users said they never received the promised grocery cards or dental care -- and chasing those offers can have unintended consequences.

In a May 2022 letter to US congressional leaders, the National Association of Insurance Commissioners said states had seen an uptick in consumer complaints about "inappropriate or confusing marketing practices" that lead people to enroll in plans "without adequately understanding the coverage."

"It is possible for some people to get some of the stuff that's being advertised," Lipschutz said. "But what's completely left out is that you have to join plan X in order to do it, which could completely disrupt your health coverage."

To avoid getting duped, Amy Nofziger, director of fraud victim support with AARP, once known as the American Association of Retired Persons, suggested people "tread lightly and do your research."

"A lot of ads that are on social media are not vetted the way that people think they are," she said.