High medical bills are the leading cause of bankruptcy filings among seniors and those under age 65. But typically, those bills, which are classified as unsecured debt, are discharged in full at the conclusion of a Chapter 7 bankruptcy. But if the senior is not eligible for a liquidation bankruptcy, or they choose a Chapter 13 repayment plan, those bills may not go away.

"In a Chapter 13 case, depending on the net monthly income and the amount of secured versus unsecured debts, a debtor may be required to pay a portion of the medical bills and other unsecured debt," says Gallagher.

It's also possible -- though rare -- that the senior might have medical bills that are considered secured debt. "In some rare instances after a medical provider has obtained a judgment against a debtor, the debt would be considered a secured debt, which means that the provider has a judicial lien against all of the debtor's property."