Can a new healthcare rep form replace the one originally done?

She still is mentally competent.

Since your mother did not sign the form when it was completed, it is not a legally binding document.

You cannot have her sign it now, since she has been diagnosed with dementia and cannot enter into a legally binding contract, which a Representative Agreement is.

You need to sit down with your bother and the lawyer handing your mother's affairs and sort this out properly.

Judy, I misunderstood and thought the health care proxy your mother's doctor provided was already signed.  If not, and she's been diagnosed with dementia, whether or not it would be valid will depend on if your mother understands what she's signing.   

And thanks for responding to my posts.  At least I know someone's reading them !  Some people post and never come back again.

Sure hope this situation works out well for you.

Judy, when my bro fell ill it was suggested in hospital that, as my health care POA was very old, we do a new one and go through it all again, and we then called in the notary to witness the signatures. As I understand it the NEW replaces the old. Yours is witnessed and/or notarized, as you said. I believe it is the one that will be accepted as the newest. If someone is going to now contend that your isn't legitimate I guess you are looking at court fight? You two would not be able to work together? Because this might otherwise be yet another sibling court fight? Are there major things about which you disagree as regards her health care moving forward?
If your document attests that she understands she has made a previous POA for Health and that she understands this one she made with you supersedes it, then it means that the latest one made with you is the one that has standing. However she cannot sign anything now due to the uncertainty of her mental status and diagnosis and the possiblity of dementia. At least not without a doctor attesting she is capable of understanding this, and a lawyer understanding she understands what she is signing.

Adding something else...you do understand that the medical tasks you handle now aren't necessarily the only ones addressed in any health care proxy?   That typically life-saving measures and DNR issues are included as well?   

Taking care of meds and visits to the doctor are part of a health care proxy, but not the full spectrum.

And a well drafted health care proxy SPECIFICALLY addresses those life-saving measures. 

I'm not trying to insult you, just to clarify the authority you will have when the time comes.

Well, I just lost the entire message I've spent some time on; I've been having problems posting here for the last several days.  

So, just to cut to the chase (I can elaborate later if you like),
the wording "I understand that if I have previously named a healthcare representative the designation below supersedes (replaced) any prior named Healthcare Representative(s)" should act as elimination of your brother's previously granted authority, even though the document appointing him PROBABLY should have been amended to affirm that he still has the financial/business proxy.

I'm assuming though that the attorney signed as witness to you and your mother's signatures, as did the notary?  If the notarization took place separately, there is a problem with the validity of the document.  

I'll try later to elaborate if it helps you but right now I'm fed up with having what I write blocked by some kind of posting malfunction.

I am pretty sure that she had some kind of dementia in Dec last year but wasn't diagnosed until June of this year.  The form says "I understand that if I have previously named a healthcare representative the designation below supersedes (replaced) any prior named Healthcare Representative(s)".  So what does that mean?  Just because my brother is Durable POA that what I signed and my mother saw me sign still doesn't hold anything?

Hmm...perhaps what the doctor had you sign was a HIPAA release? This allows the docs and staff to discuss your mom's medical info with you, and for your to provide input to them that they will accept. This is different and separate than the medical PoA. This is what I have with 4 elderlies I manage care for, and I also have medical PoA for them, but still needed this form to be signed by all of them. I'm in MN and my LOs are here and in FL. You are in IN, not sure if it's just very different a process there. I've never heard of a doctor giving a medical PoA form to a patient. Is your brother also in IN? Someone from your state might need to answer your question. You may also be able to contact your area's council (or agency) on aging...they can answer many questions and have resources.