As my mother’s daughter, am I allowed to view copies of POA, Medical POA, or any other legal documents?

" I just would like to be a part of mom’s medical care."

Do you mean you want to provide hands-on care? Like a family caregiver? Or because you are a qualified aid or nurse? Or do you mean you want to be a medical decision-maker for her? If so, you cannot invite yourself to be her medical decision-maker unless you are her medical PoA or legal guardian.

Anita
Your mother, at some point, may have given your brother her POA. It is her right to give her POA to anyone she chooses. As her POA, your brother, does not have the right to divulge your moms business to you or anyone. Your mother’s wishes are what the agent (brother) is supposed to honor. Her wishes are hopefully spelled out in the POA.
If brother refuses to share the information as to whether he is indeed her POA and if mom is not able, then you might pay attention to how easily he is able to access her bank accounts, medical records and other important records that legally require this type authorization. Your being your mother’s daughter does not in and of itself give you legal rights to her private business.
Having said all that, if you ever feel your mom is not being fairly treated by your brother, you could discuss this with an attorney to determine your best course of action.
A guardianship has more authority than a POA. It is expensive and sometimes difficult to prevail.
Have you tried speaking with your brother about your moms health? I found it worth mentioning that you were fine with him having the POA. Does he know that? It’s really not easy being a POA. It can take a toll. Here is a quick link from this forum on POA. It might be helpful.

https://www.agingcare.com/search?term=POA

Firstly, 'age related decline'... Alzheimer's Disease & others that fall under the Dementia umbrella label - we do have increased risk of these as we age - but it's not a given. (Some folks are sharp til the end, like Betty White at 99).

So I'm wondering what Mother's actual diagnosis is - if indeed she has one. Or is this part of the issue? That you have been kept in the dark?

While I feel a daughter has a moral right to be in the loop regarding her Mother's health, there are privacy laws for reasons. Many families have estranged relatives & do not want their personal information or health to be disclosed to them.

Hopefully someone can advise you from the legal point of view.

I can only take the social point of view, & to suggest having an honest chat with your brother. Leave any history out of it. Ask the details: who is named POA, MPOA, has a Doctor declared & written that your Mother is unable to make decisions?

Maybe he will be open & willing to show you the documents & fill you in?

But if he is vague, unwilling to disclose, obstructive...?? I guess you will need your own legal council to formally ask him instead.

A POA is obliged to act as the incapacited person would have. If you feel he is making decisions not in accordance to Mother's values, you may need to formally/legally challenge him too.

You could ask to see proof that he actually holds medical power of attorney, but he does not have to let you have a say in her medical decisions if he does hold it. It'd be nice if he did, but I'm going to assume you two don't agree on those decisions.

This is the exact reason why attorneys do not recommend giving more than one person POA -- there is often a clash between them when it comes to decision making.

The best person to hold POA is the one who'll carry out your wishes regardless of their own. Sometimes that's not the person closest to you.

Would mom be able to provide the documents to you? Did an attorney prepare them?