Transcript for Medicare Fraud: Grandmother Goes Undercover
-- the FBI has been cracking down on Medicare fraud it is estimated that 10% of the Medicare budget billions and billions of taxpayer dollars. Our loss to cheats and scam -- And ABC news found a grandmother willing to go undercover to show you how they do it. Here's ABC's chief investigative correspondent Brian Ross. We went to the tiny border town of McAllen Texas. Don't sound as the square dancing capital of America. -- -- -- -- less well known to federal investigators as a hotbed of -- taking advantage of Medicare. The health care system for senior -- for any patient with a Medicare number. Even someone as healthy as our golf playing undercover -- 82 year old Doris pace a potential windfall -- dishonest home health care companies. As long as there's a doctor's certification that the patient is home out there lying in order to steal. From you and me and the taxpayers in the case of our undercover -- She was personally taken by a so called recruiter for a home health care company to a doctor he chose for the all important certification process. In the examining. Our grandma told the doctor that other than some high blood pressure and arthritis she was in -- -- You don't have any feedback -- are steps Spain. Yet the home Health Care Reform for Medicare would show a patient who needs assistance for all activities unable to safely leave home unassisted. Authorities -- the diagnosis could have opened the door for a huge fraud. It's worth tens of thousands of dollars a month that's all justified by the -- -- and indeed the very next day. A nurse working for the home health care company showed up to treat -- supposedly homebound undercover ground. For diabetes and other ailments and did not have. Over the course of a month. But health care company and the doctor billed Medicare almost 18100 dollars until we pulled the plug on -- want to ask you about the doctors had media and everybody did not want to talk about why she certified the patients as home about. And I don't -- diagnosed with diabetes which it. Anything you buy -- make up these diagnosis from. The very serious allegations man. The -- -- later admitted there were errors on the health forms that said someone other than a doctor or her nurses he did not say who put him bogus diagnosis. Federal authorities tell us tonight they've now open an investigation. And that's -- that 18100 dollars in suspect Medicare billing for undercover grandma. ABC news is told the government will reimburse any cost at least we can do thank you Brian and you're investigative grandma is great -- --
This transcript has been automatically generated and may not be 100% accurate.