When asked why he robbed banks, Willie Sutton, the notorious bank robber from the 1920s, reportedly said, “That’s where the money is.”

Sutton’s answer could explain the massive amount of fraud in Medicare and general health care. There’s lots of money in health care.

With health care spending accounting for about 18 percent of annual economic activity in the United States, the medical industry is a bountiful feeding ground for criminals. Given that Medicare pays out $600 billion annually and Medicaid makes $425 billion in payments every year, the federal health care payment system is, as Sutton might say, where the money is.

In fact, defrauding the Medicare and general health care market is so lucrative that law enforcement reports say criminals are leaving the illegal drug trade in favor of health care fraud, which is less dangerous, poses less risk of being caught and offers better hours and working conditions.

In recent years, Florida has been a hotbed of Medicare fraud, which is not surprising given the large population or retirement age, Medicare patients.

Law enforcement efforts have made some progress in Florida, but fraud investigations suggest the criminals don’t leave the business, they just go somewhere else and run the scams again.

News stories about Medicare fraud appear weekly across the country. Despite increasing investigations and prosecutions, Medicare fraud seems to be expanding.

The scams can involve criminals filing false claims using identity theft. In many cases, an unethical doctor, health care clinic, or home health care provider files false claims. In other cases, the fraud happens when an otherwise legitimate business, such as a hospital or medical practice, games the system to increase reimbursements for care provided to patients.

Earlier this month, National Public Radio reported on a study by the Government Accountability Office that discovered overpayments of abut $70 billion a year by Medicare to private health plans. In the broader health care industry, it’s estimated $275 billion is stolen each year.

The critical GAO report echoed earlier reports that found billions of dollars being improperly spent for inflated billings or paying for services that were never provided.

The $70 billion figure is stunning, and many believe it’s much higher. The growth in this type of fraud suggests the federal government needs to do more to stop the crimes. A special Medicare Fraud Strike Force was created in 2007, but the fraud continues to grow, despite numerous prosecutions and convictions.

Another shocking part of the report found that the Centers for Medicare and Medicare Services spent about $117 million boosting audits to catch the inflated payments — but was only able to recover about $14 million.

The latest report should lead to a shake-up in Washington to slash the waste — theft, actually — in Medicare reimbursements. But taxpayers can only shake their heads when they learn that a 2014 GAO report, titled “Medicare Advantage Money Grab” warned of $70 billion in waste through improper fees from 2008 through 2013. Still the waste and fraud continues to grow.

Federal bureaucrats deserve criticism for not making more progress in stopping Medicare fraud. But in their defense, it’s a massive and complicated problem. And with 4.5 million Medicare claims being processed every day, the ability to scrutinize every claim for fraud, cheating, or upcoding (inflation of services) is impossible.

Another problem is that while the criminals are highly motivated by big potential profits, the chances of being caught are quite low. It’s also true that hospitals and doctors are under increasing pressure to make profits, so the temptation to game the system by so-called upcoding to increase reimbursements is constant.

Federal officials tasked with stopping Medicare fraud seem overwhelmed. But the fraud in health care, which represents nearly a fifth of domestic spending, requires a more serious — and more effective — effort to stop the wasting, or theft, of billions of taxpayers’ dollars a year.