How can I prevent a deficiency lawsuit?

Generally you cannot be responsible for the debts of another.  There are some exceptions: There are two options to handle someone's estate after they die if there was not a Living Trust set up:  The first is to probate the estate.  In California if the assets are over $100,000 it has to go through probate.  The second is a small estate procedure which is much easier, quicker and inexpensive for a smaller estate.  In probate, the creditors much file a claim or they get nothing out of the distributions.  In the second instance, the beneificiaries could take on the liability of any unpaid creditors ONLY up to the amount they received from the estate.  This is California law, though, and Florida may be different. Additionally, there are two ways to foreclose on property - one is through a trustee's sale like you see most often here in California.  In this procedure there is no deficiency judgment available to the creditor.  The second way is through a judicial foreclosure and your question states that is the case for your mom's home.  A judicial foreclosure allows a deficiency judgment on any unpaid balance.    In your case, you mention that there is a lawsuit which could result in a deficiency judgment however here in California you would not be liable as you received nothing from her estate.