What needs to be proven for abandonment of property?

I am presuming that if you owned the home as a married couple, that your divorce proceeding did not address the division of this property since you are asking this question.  If you aren't certain of that, you should check your divorce decree to see if it speaks to the issue of maintaining and dividing this house. Assuming the house was not addressed in your divorce, you are entitled to seek partition of the house.  It will likely be sold to either one of you or an outsider, with the net proceeds of the sale (if any) divided between the two of you.  Before you seek partition, you may want to see if the house can be sold for a profit so that you don't have to bring any money to the closing.  Assuming it is sold and there are net proceeds, the court will take into consideration any agreements you have about maintaining the property or your respective contributions to maintaining the house and paying the expenses.  The court can award something other than a 50/50 division of the proceeds. Your ex being in jail presents a lot of practical problems.  It's not impossible to pursue partition, just very difficult with the other person being in jail.