I've learned some things about Social Security that might help others caring for their parents. There is a form which you can fill out for SS to become "payee" which allows you to speak with them or act on your parents' behalf. This is not a POA (Social Security does not recognize a POA) The form must include a form signed by a doctor indicating your parent cannot manage finances on their own.
I was lucky enough to have a very nice person at Social Security explain it as my initial fear was they were going to send checks to me and it would mess up my own taxes.
She explained that becoming payee does not mean the check goes to the payee, or that it goes on your taxes. It simply means SS now recognizes you are legally managing their Social Security income on their behalf and allows SS agents to communicate with you to answer questions, etc. I would assume this also include Medicare issues as well. A good thing to have!