Ben Williams of Seattle recently received a phone call from a man claiming to work for the federal government. The caller said Williams would receive a new medical card that would cover 100 percent of the cost of surgery, hospital visits, medicine and all medical needs. In exchange, he wanted Williams’ banking information, his account number, the name of his bank and authorization to withdraw $329 for a one-time fee.

Williams is a disabled veteran whose medical expenses are already covered, so he told the caller he wasn't interested.

"He put his supervisor on to try to get more information out of me. I did not want to give out that information, so I hung up," said Williams.

Williams thought it was over until he received this message at a different number -- his cell phone.

"Mr. Williams, please pick up the phone. This is a medical call. You need to carry this card. Please pick up the phone," the message said.

Williams didn't pick up, and didn't lose any money, but he did want to warn other seniors.

"My friend was sitting here and I was talking to them about it and they said, 'Call channel 7. Call Amy Clancy,'" said Williams.

The brother of a Federal Way woman had the same reaction after she received a similar call.

"He said, 'Why don't you call KIRO and tell them about it?'"

That woman doesn't want to be identified, because her call was more frightening.

"From the very beginning, the red flags went up," she said.

Her caller claimed to be from Medicare and also offered her increased medical and dental coverage.

In fact, the caller arranged to meet the woman at her house the next day to discuss it, but right before their scheduled meeting she got nervous and left but now wonders what would have happened had she stayed home.

"It doesn't give you a very secure feeling -- it really doesn't," she said.

Chuck Harwood is with the Federal Trade Commission.

He worries that this woman's caller could have been targeting her for more than just money.

"The idea of setting up a meeting, I find very disturbing," said Harwood.

Harwood said he wants all seniors to know these offers are not legitimate.

"Medicare and Medicaid will not call you on the phone and offer you supplemental coverage. If they are changing their coverage, if they are making changes in what they are doing, you're going to receive a letter or you're going to receive some sort of communication in that fashion. You will not receive a personal phone call," said Harwood.

Those who've received the calls have their own advice.

"The government doesn't charge you for a medical card," said Williams.

"You don't have to talk to anybody you don't want to talk to! Hang up!" exclaimed the Federal Way woman who received a call.

At the advice of the FTC, that woman called the Federal Way Police Department and filed a report, because the callers know where she lives. And when she didn't keep their appointment, they called back to find out why.

The FTC and the Attorney General's Office told KIRO 7 Consumer Investigator Amy Clancy that seniors are more likely to be polite to these callers, but you don't have to be. If it's something important, you'll get something in the mail.

If you've received a call from someone claiming to be from Medicare or Medicaid, and you believe it's a fraud, call 1-800-MEDICARE.