I've been paying mom's mortgage among other expenses since she died in February. What can I claim?

First of all, a POA is not valid after your mom's death. What you need now is an executor for her estate. Is there a will? If so, there may be someone named as executor in the will. You need to know who is on the title for the house. Are you living in the house, or will it be sold? If your mom is the only one listed on the title, I believe that you will need an attorney to either transfer title to you and/or you and your siblings, or to sell the house. Keep records of what you have spent to maintain the house since your mom died, and submit them to the attorney for reimbursement from the assets of the estate. Unless your name is on the mortgage, you are not legally obligated to make the payments. Of course, if no one is making the payments, the mortgage holder has the right to foreclose on the house. I do not believe that you can deduct for tax purposes any payments that you are not legally obligated to pay, but this would be another question for the attorney.

Wow, that's a good question. (I also have two sibs that are MIA.) I would call your accountant if you have one. You might also consult an elder care attorney. I asked my accountant about driving my mom to appointments, and I was not entitled to anything. Good luck; you sound like a wonderful daughter. (Does your Mom have all her paper work, such as POA, in order?)