As my mother's POA, do I still need that other document to speak to Medicare on my Mother's behalf?

@mrtvz64 - This is a great question that we get all the time in our call center. Thanks for asking. The short answer is that you need to have a Medical POA.
The Medical or health care power of attorney (POA) is a legal document that designates you — referred to as your mother's health care agent or proxy — to make medical decisions for her if she can't do that for herself.
These Medical POAs are different from a power of attorney that authorizes you to make financial transactions for your mom.
I hope that helps!
Ross

If you have Durable POA then that gives to the right to speak on you parents behalf. You will have to submit a copy for there records. And depending on there procedure there might be a waiting period so POA documents can be reviewed. If you have just a simple question for medicare they should answer you directly without POA. I recently call medicare and inquiried about mom's Hospice I gave them moms info and introduced myself and they answered what I needed. However, If it is bill related or something more personal then they will probably want Durable POA proof. But they will tell you if they do or not. So give them a call make sure you have moms medicare card in front of you, her DOB, Soc. sec#. Like I said they might be able to help you based on questions asked w/o POA submitted.

What address do I sent the POA and caregiver official papers to Medicare

When I contacted them about my cousin, I was told that I had to be appointed the Representative Payee through Social Security.