Federal task forces are using billing data and whistleblowers to take down large-scale, multimillion-dollar schemes.

Imagine your eye doctor has diagnosed you with wet macular degeneration, a rare condition that could cause vision loss.

You follow your doctor’s advice to get further diagnostic testing, laser eye surgery, and treatments that could increase the risk of a heart attack.

It might be difficult and painful, but you’ll do anything to prevent vision loss.

Now imagine, months later, you and more than 500 patients of two Florida eye clinics discover your doctor, Dr. David M. Pon, has been defrauding Medicare.

“The fraud committed by Dr. Pon, a well-trained ophthalmologist, was particularly egregious,” federal prosecutor A. Lee Bentley III said in a statement after Pon was convicted of 20 counts of healthcare fraud last year. “He instilled fear in his victims, performed unnecessary and sometimes dangerous medical procedures on their eyes, and asked the taxpayers of this country to pick up the tab.”

And they did to the tune of $7 million.

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Pon’s eye scheme had one major flaw. While wet macular degeneration is responsible for 90 percent of legal blindness, it only accounts for 10 percent of all cases of macular degeneration.

When comparing Pon’s billing records to those of other eye doctors — a process called peer comparison analysis — federal investigators found something amiss in the data.

And there’s a lot of data. Medicare sees about 4.4 million claims every day, so investigators are focusing on better ways to sift through that data to find fraud, waste, and other problems.

Caryl Brzymialkiewicz, chief data officer for the Health and Human Services (HHS) Office of Inspector General (OIG), said the peer comparison generator helps spot outlying doctors, as well as patterns among pharmacies and others who could be gaming the system.

“Either the data can lead us to somebody that is potentially committing fraudulent activity, or our investigators can have a hotline call where they can have a witness or a whistleblower come tell them that they suspect criminal activities happening, and we can bounce that against the data,” she said earlier this month on the OIG’s podcast.

Between whistleblower complaints and the oceans of data, investigators are able to connect the dots in small and large-scale operations that bilk the government out of billions every year.

Earlier this month, the Department of Justice (DOJ) announced criminal and civil charges have been brought against 301 people — including doctors, nurses, and other medical professionals — for allegedly falsely billing Medicare for more than $900 million.

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In March 2007, the OIG, DOJ, Offices of the United States Attorneys, the Federal Bureau of Investigation (FBI), and others formed the Medicare Fraud Strike Force.

Since then, it has charged more than 2,900 defendants who falsely billed the Medicare program for over $8.9 billion.

That’s still a small fraction of the totality of fraud inside the medical industries.

As healthcare and social assistance are the largest industries in the United States, fraud is a major industry of its own. Some experts estimate it could cost taxpayers hundreds of billions of dollars every year.

According to the Centers for Medicare and Medicaid Services, of the $491 billion spent on Medicaid in 2014, $17 billion went to fraud, waste, and abuse.

Medicare now spends more than $600 billion a year providing health insurance to more than 54 million people 65 years of age and older.

How much is lost to fraud? That’s anyone’s guess.

Both Medicare and Medicaid are on the Office of Management and Budget’s “high-error” list because there are more than $750 million in improper payments every year.

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One of the largest running scams — which included television ads to recruit Medicare patients — was providing electric scooters to people who didn’t need them.

The chairs cost about $900, but Medicare would reimburse up to $5,000, leaving plenty of profit margin for paying people to recruit patients and pay off doctors, according to a Washington Post investigation.

That was before anyone was checking. Now they are, so the criminals have moved onto other scams.

Now the easiest way to commit healthcare fraud is to simply bill for services and not perform them.

That’s how the majority of fraud cases happen, according to a Government Accountability Office (GAO) report filed earlier this year. The office examined 739 fraud cases from 2010.

Of those cases, billing for services not provided or ones that were not medically necessary accounted for 68 percent of all the cases.

Others included falsifying records, paying kickbacks, or fraudulently obtaining controlled substances.

In 62 percent of the cases, providers were complicit in the schemes, and beneficiaries were knowingly complicit in 14 percent of the cases.

Individual doctors, clinics, and others involved in these schemes can glean millions of dollars from the Medicare system before they’re caught.

Pon’s net worth, not including his millions of dollars in holdings in China — was valued at $10 million, according to the Orlando Sentinel.

In the new $900 million case, which involved numerous sites across the United States, alleged schemes involved kickbacks for supplying patients’ Medicare information for fraudulent bills and then laundering the money through shell companies.

Of the 301 people involved, 61 were licensed medical professionals.

One case in Texas involved unlicensed people performing medical services and billing Medicare as if a doctor performed them.

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As Medicare is for people 65 years of age and older, large-scale fraud cases typically stem from states with high concentrations of residents who are older adults.

At the foreground is Florida, where nearly 20 percent of its residents are over the age of 65.

In April, 25 people in the Miami area were arrested and charged for allegedly defrauding the Medicare Part D program, the government’s $120 billion prescription drug program.

The defendants were accused of fraudulently billing for prescription drugs that didn’t go to Medicare beneficiaries.

“Unfortunately, South Florida remains ground zero for these types of scams,” Assistant Special Agent in Charge, William J. Maddalena of the FBI’s Miami Division, said in a statement.

A recent case in eastern Michigan involved luring patients with kickbacks to go into physical therapy clinics to obtain $36 million in unnecessary prescriptions for drugs like hydromorphone, methadone, Demerol, oxycodone, and fentanyl.

Not only did the Michigan case contribute to Medicare fraud, it also helped fuel the availability of powerful painkillers in the midst of an opioid addiction epidemic.

Doctors across the country who were part of these “pill mills” are now facing criminal charges, including defrauding Medicare. Some of the cases involve murder charges related to the deaths of their patients.

“While it is impossible to accurately pinpoint the true cost of fraud in federal healthcare programs, fraud is a significant threat to the programs’ stability, and endangers access to healthcare services for millions of Americans,” Inspector General Daniel Levinson of the HHS OIG, said in a statement.