(AP) -- The first box that arrived at Shirley Shupp's door was filled with braces to help with her arthritis. Then came a motorized scooter, just like the one the 69-year-old already owned. She hadn't asked for any of it - but Medicare was apparently footing the bill.
"There was just something that wasn't right about it," the Houston woman said.
So Shupp contacted her local Senior Medicare Patrol, which did its own research and then referred the matter to investigators. The equipment, worth thousands of dollars, was returned, the case was handed over to prosecutors and the perpetrators were charged with Medicare fraud.
The Senior Medicare Patrol is one of the least-known forces in the government's effort to eliminate such fraud, which drains billions of dollars a year. But it is seen as a valuable part of the Obama administration's bid to overhaul health care and bring down costs.
The 4,700 senior citizen volunteers who serve as the government's eyes and ears have been credited with saving taxpayers more than $100 million since 1997. The program relies on elderly people to apply a lifetime's worth of common sense and skepticism.
"They can tell when something just doesn't feel right to them," said Anne Gray, who works on the SMP program in Santa Ana, Calif.
The patrol, which evolved from another program founded in 1995, now has at least one unit in every state.
SMP sends its volunteers to senior centers, retirement communities and elsewhere to encourage Medicare beneficiaries to guard their personal information, beware of too-good-to-be-true offers on medical equipment and carefully review their benefit statements. The patrol also collects tips on potential scams and fields calls from senior citizens who believe their Medicare accounts have been fraudulently billed.
When all they have is a whiff of something fishy, SMP participants often keep probing until they have enough information to send on to the FBI and investigators with the Centers for Medicare and Medicaid Services.
"It really is detective work," said Barbara McGinity, director of the SMP in Houston.
Patrol volunteers have witnessed all kinds of schemes. There are fly-by-night clinics where patients endure multiple tests at the hands of staff members with dubious credentials. Patients may be followed home from the hospital by companies selling home health services, scooters, glucose monitors or psychotherapy.
Often, senior citizens are persuaded to give up their personal information with an offer of something they need, such as transportation to kidney dialysis appointments.
"They get their number and they pass it around," Gray said. "They have a ring where they're selling it."
Beneficiaries may have no idea their identities have been wrongly used unless their accounts are frozen for unusual activity or they try to obtain something the government already bought for them, such as a pricey hospital bed or wheelchair.
The Obama administration says eliminating Medicare fraud is key to overhauling the health care system. But agents and prosecutors tackling the issue are relatively sparse. The patrol helps fill in the gaps.
"There is no substitute for beneficiaries and on-the-ground resources to help us know where fraud is occurring and where problems are arising," said Kimberly Brandt, who oversees Medicare anti-fraud efforts at CMS.
All told, scam artists are believed to have stolen about $47 billion from Medicare in the 2009 fiscal year, nearly triple the toll a year earlier. Medicare spokesman Peter Ashkanaz said that since the Justice Department and Health and Human Services formed a task force after President Barack Obama took office, charges have been filed against 103 defendants in cases involving more than $100 million in Medicare fraud.
For every Medicare thief the senior citizen volunteers successfully pursue, McGinity said, it seems there are dozens more.
"Sometimes we feel like we're really beating our heads against the wall," she said.
Explore further: Chile's Bachelet sends abortion bill to Congress