PITTSBURGH -- An obscure Pennsylvania law that hadn't been enforced in decades is suddenly alive again -- and it could cost you thousands of dollars.

The law can force adult children to pay their elderly parents' nursing home bills, so if mom or dad can't pay, you have to pay.

Team 4 investigative reporter Jim Parsons says it's known as the filial support law, and its origins date back hundreds of years. A handful of law firms around the state are suddenly using the filial support law to go after adult children whose parents owe money to nursing homes.

Video - Watch Jim Parsons' Report

"I'm telling you, it'll bite you. You'll think it's nothing, but it'll bite you," Don Grant said.

Grant isn't talking about his dog. He's talking about a Pennsylvania law that has been in hibernation for decades -- and when it woke up, the law's bite was worse than its bark.

"I was stunned. You got to be kidding me," Grant said.

Grant received a collection letter last year from a law firm representing a Delaware County nursing home where his mother stayed for rehab following knee surgery. The letter said Grant had to pay his mother's outstanding balance of more than $6,000.

Grant has been estranged from his mother most of his life and has nothing to do with her finances.

"We hadn't spoken in probably about two or three years," Grant said. "I was pretty much raised by my grandparents."

So Grant sent a letter back to the nursing home's lawyer, saying he wouldn't pay a dime. That's when he got hit with a lawsuit, which he tried to handle without an attorney and lost.

"And it was filed, and there's the $8,000 judgment against me, right there, just like that," Grant said. "That affects anything I do. If I want to get a loan on the house, this is going to come up."

So why doesn't Grant just pay off his mother's debt?

"I probably could," Grant said. "However, am I going to? No. It's not my responsibility."

But Pennsylvania's filial support law says otherwise. It goes back to colonial times, when the state assumed children -- often living on a farm -- should take in mom and dad if they were unable to support themselves.

"The act was re-invigorated a few years ago," said Lawrence Frolik, a professor in the University of Pittsburgh School of Law. "It was re-passed by the Legislature, and I think that brought it to the attention of a lot of nursing home managers who said, 'Oh, there is this act on the board, they've re-enacted it, so maybe it has some vitality.'"

---

More On Filial Support Law - Watch Jim Parsons' Interview With Lawrence Frolik

---

Presbyterian SeniorCare in Oakmont was the first nursing home in Pennsylvania to use the filial support law in modern times.

"This was very much an extraordinary circumstance, and the approach we took was very much last resort," Presbyterian SeniorCare CEO Paul Winkler said.

Presbyterian invoked the law to collect from a daughter who had transferred her mother's money to herself.

"So it seems pretty fair to go back to that child and say, having taken the money from your parent and left them destitute, you should now pay for your parent's needs," Frolik said.

No one argues that Presbyterian used the law fairly. It's what happened after that case -- like what happened to Don Grant -- that has caused anxiety.

"This law does not make people happy," said Carol Sikov Gross, an elder law attorney. "It's one of those things we'd like to have it repealed."

Sikov Gross has seen a growing number of filial support lawsuits filed by nursing homes in recent years.

"And these people come in finding out -- 'I thought I was safe, I thought I was protected, and suddenly, I've got to pay all this money for a bill that's not even my bill. It's my mother's bill. It's my father's bill. Why do I have to pay this bill?'" Sikov Gross said.

The chairman of the House insurance committee said he didn't know anything about the filial support law until Team 4 told him. But when we did, he instantly said he wants to repeal it.

"If you could send me that information on behalf of the legislation, I certainly would introduce it because I think it's very unfair for family members to pick up debt that they haven't acquired," said state Rep. Tony DeLuca, D-Penn Hills.

Don Grant couldn't agree more.

"I don't think anything can be done for me. However, I want Pennsylvania people to know about this thing," Grant said. "You're responsible for your own actions. You take care of it. Don't lay it off on somebody else. And if it got me, it'll get other people."

What can you do to protect yourself and your loved ones from a nursing home that wants to collect?

First, if you want mom and dad to qualify for medical assistance to pay for a nursing home, make sure their financial paperwork is in order. You'll need to show where and how every dollar of their money has been spent, going back five years.

Number two: Don't let them give their house away to you or anyone else. That will disqualify them for assistance.

And lastly, spend a few hundred bucks now and hire a good elder law attorney for advice. It could save you thousands later.