When you pick up your pills at the pharmacy both you and your insurance pay the bill.

But experts tell the News 4 I-Team taxpayers may also be footing the bill for prescriptions billed in your name without your knowledge.

"Here at Leisure World, people my age tend to take medication,” Norman Eisenberg said. “There's one I need to take every day and then there's others that I take as needed."

This includes Lidoderm patches filled with a strong pain killer. With a $70 co-pay, Eisenberg said he doesn't use the patches very often.

He told the I-Team his caregiver returned from his pharmacy with bottles he needed plus a box of Lidoderm he didn't want.

“I called up the pharmacy and asked, ‘Why did you refill this?’ and they told me that their policy was they call periodically and ask if they want their prescriptions refilled. And if people don't answer the phone two or three times, they just automatically go ahead and refill it," Eisenbern said.

It's called automatic refill, and patients sign up at their pharmacy. CVS's website promises there's "No need to call in or drop off refills...We'll call when your refills are ready and contact your prescriber when you run out."

Pharmacist Joe Zorek worked at CVS for more than 30 years.

“The patient begins to build up medicines and has no idea why, especially senior citizens," Zorek said.

Zorek said the company demands a 40 percent “ReadyFill” enrollment rate at all of its stores. The News 4 I-Team obtained internal CVS documents showing how the company keeps track of each store’s numbers.

Zorek said CVS punished him after he complained about its use of these measurements and has now filed a whistleblower lawsuit against the company.

"What happens a lot is we see allergy medicine,” Zorek said. “It's seasonal. As a result, once the season is over, you're fine. But if you keep refilling the prescription, it will just build up for months until the next time you need it."

At his store, Zorek said they processed 4,200 prescriptions a week with an estimated 100 auto fill prescriptions unclaimed.

CVS pharmacists are supposed to return them to the shelves and refund the insurance companies.

But Zorek said sometimes it didn't happen.

"In a busy situation, if the process isn't correct, you're being paid for medication you really never delivered," Zorek said.

According to Public Citizen's Dr. Sidney Wolfe, that could be considered fraud.

"If, for example, the insurance company is Medicare or Medicaid, this essentially falls under the federal False Claims Act,” Dr. Wolfe explained. “If you're submitting a false claim, and in this case the false claim is that you gave medicine to a patient that they never got, the government is paying for something that didn't possibly have any benefit to the patient, so that is a false claim, it's fraud and it could be prosecuted."

CVS "received a subpoena" from federal investigators "requesting information concerning" its "automatic refill programs," according to the company's most recent financial report to the US Security and Exchange Commission.

CVS would not comment on why the Justice Department wanted its records, but released the following statement to News4:

“We have strict procedures and processes in place to ensure that we are only paid by insurers for those prescriptions that are picked up by our patients… Only prescriptions that are intended to treat chronic disease and have refills remaining are eligible for ReadyFill. Once enrolled in this program, patients can stop the service for any of their medications at any time.”

All of the experts News4 I-Team talked with said auto refill programs are great for people who are especially forgetful and on a long-term medication for something like diabetes or high blood pressure.

However, they warned no matter what pharmacy you use, experts say you need to pay attention if you're on the auto refill list because it can “lock” you into using that pharmacy chain, meaning you can’t change pharmacies or get medicine while you’re traveling because the pharmacy may have already charged your insurance company for your next refill.