June Smith had a funny feeling the medical charges were fraudulent. The 72-year-old New Yorker’s first clue? The bill for a pregnancy test.

Beginning in 2006, Smith’s personal information—including her Social Security number—was used to charge Medicare for tens of thousands of dollars of medical services in her name. Despite her attempt to alert officials, she says, Medicare paid the bills. Though Smith and her husband, Thomas, didn’t incur any personal charges from the fraud, they worried they’d reach a Medicare benefits cap and ultimately be denied legitimate services they might need in the future.

The Smith case illustrates the challenges many victims of medical identity theft face—often when they’re at their most vulnerable due to age, infirmity or limited resources in retirement.

“It’s important for people like me to have their eyes open,” Smith says. She hopes her story, recently featured on WABC-TV’s “7 on Your Side,” offers a valuable lesson for other potential victims.

Medical identity theft begins when someone gains access to a victim’s personal information. A fraudster can rack up medical charges very quickly. And those charges can cost insurance companies, Medicare, and victims—through assessed co-pays for services never received.

It’s often difficult to untangle what has happened, and to get medical providers and insurance companies to understand that a fraud has taken place.

“Why are you paying these bills?” Smith once asked a Medicare representative, after explaining her situation. The rep responded, according to Smith: “‘Because they come to us.’”

Through her homeowners insurance, Smith reached Cyberscout fraud specialist Mark Fullbright. After an investigation, he discovered that many of the supposed doctors and medical entities making the charges weren’t licensed as physicians or operating as legitimate businesses. They appeared to be fictitious people and institutions created by scammers who were still receiving very large checks.

Fullbright detailed those particulars in letters he wrote to various authorities, including Medicare officials. And while he never got direct responses, Smith finally received a letter from Medicare last year. The letter stated that one group of charges was considered fraudulent and would not be paid. Medicare was finally paying attention to what she says she had been saying for years. “It was just a sigh of relief,” Fullbright says of that first acknowledgment. “After years of her complaints falling on deaf ears, they were starting to look into whatever the complaints were and (understand) that she may be right.”

Four years after the first suspicious bills, Smith’s ordeal isn’t over. She still gets notices of charges to Medicare that are obviously wrong. But Medicare has stopped paying them.