Ogrosky said criminals' forms are often filled out more completely than actual health care providers'.
"Real hospitals and doctors who are struggling every day to keep up with the paperwork sometimes miss things ...whereas if you are a criminal trying to steal, all the forms look perfect every time because the whole goal of the enterprise is to check the right boxes," he said.
Medicare makes life very easy for criminals. Unlike credit card companies that stop payment the second a suspicious charge is made, "Nightline" learned Medicare is slow to respond even when people call to tell them about fraud.
Paula Teller spent three years trying to convince Medicare that fraudulent charges were being made using her Medicare number.
"Every week there was a charge of maybe $1,000 or $2,000," Teller said, "Thousands of dollars for treatments that I didn't even know what they were actually -- some kind of diabetes medication. ... I called Medicare and they kind of questioned if I was sure I hadn't had it done."
Teller estimates that $50,000 in phony claims was made under her Medicare card.
Judge Marshall Ader, who sat on the Florida state bench for decades, said he even had trouble getting Medicare to pay attention. When he saw that Medicare was being billed for two prosthetic legs using his Medicare number -- for the record he has both of his legs -- he hit the roof.
"I saw that there was a report for some prosthesis that I, of course, didn't use and had never used," said Ader, who has both of his legs and no need for prosthesis. "The bill was something like $30,000."
"I called Medicare, the investigative fraud unit ...Nobody seemed to care," he said. Ader told us it took over a year to sort out the situation.
Meanwhile, criminals continue to get rich quick, often buying expensive toys from helicopters to sports cars and race horses, from these easy-to-execute scams.
Another variation of the scam took place at a phony AIDS clinic, where a patient being paid off by fraudsters made a fake Medicare claim at the facility. "Nightline" was provided with undercover video inside the clinic documenting the scam in action.
The video shows the informant following the fraudsters into a back room, where he gets a cash kickback for use of his Medicare number.
According to Piper, Medicare was billed three times a week at this clinic and paid out $10,000 per claim -- more than $30,000 a week for a service that was never provided.
"That's just per patient. One patient," he said. "So when you get a group of 10, 20, 30 patients you can see what a lucrative crime this was."
The clinic was closed, but not before Medicare paid the fraudsters $2 million. The criminals were sent to prison in sentences ranging for three to seven years.
Plenty of criminals are arrested by the FBI and the Office of Inspector General. Just recently in Detroit, where another strike team is located, agents conducted an early morning raid on a clinic that had collected $15 million in an alleged Medicare scam.
U.S. Attorney Jeffrey Sloman spearheads prosecutions in South Florida. He meets with us in a secret location and shows us the row after row of pending cases representing what he calls "over a billion dollars of fraud... probably...two billion." Sloman said: "there is definitely more out there."