Should an additional person (with POA) be added to a bank account if one of the joint owners has dementia to protect funds if death occurs?

My parents put me on their account years before it was necessary and without my knowledge at the time. I was also POA as well as their trustee, but that one account wasn't in the trust.

Since banks can be jerks about POAs, I recommend being put on the account so none of that's an issue. If your folks trust you not to drain their account behind their back, then by all means have them put you on it.

The POA is always added to bank accounts, but only as POA. That means they pay the bills signing as a POA is supposed to sign. A POA should take their papers to all banks and legal entities and be registered as POA. A POA ends with death. Upon death all account without a POD are in the control of the EXECUTOR or the WILL or the TRUSTEE of a TRUST. The work of the POA is over.
What "protection" do you feel is needed for these accounts?

As I understand it, the POA has access to any accts once the principle is deemed incompetent. You don't need to be on an acct to write checks and sign them with your name and POA after it. Always put POA after anything you sign for the principle.

I was on my Moms acct anyway but I was able to cash in her CDs to pay for her care and have the money transferred to her acct. I had no problems in my area of NJ with using my POA.

Your best bet is to go to the bank and ask an officer. There are ways that the acct can be worded.

If someone has financial powers of attorney for the person with dementia, that should be enough for the bank to allow them access to the person's accounts. Some banks prefer their own POA forms. Some banks don't like to accept POAs at all. However, some states have laws that require a financial institution to accept a valid POA, so check with an attorney if the bank is balking. Beware of becoming a joint owner on another's bank account. Some, but not all, of the problems include the fact that when the mother dies, all the money in the account belongs to the joint owner and is not considered a part of her estate. This may cause problems with beneficiaries of the mother's will. The money in the account also is exposed to the joint owner's creditors or could be made part of a settlement in a divorce. There also could be tax consequences for the joint owner. I am assuming that a valid financial POA for the person with dementia exists. If not, the person with dementia may not be able to grant financial POA to another person (the agent). You have to be mentally competent to grant these powers. In some people, competency can come and go, be good one day and not the next. An experienced elder care attorney can help. Speaking to the doctor of the person with dementia is a good idea. If a POA isn't possible and the competent partner is unable to serve as a conservator/guardian for the person with dementia, another person will have to petition the court to be appointed as conservator/guardian. Unfortunately, this can be expensive. Speak to the bank about managing her bank account with the POA. Speak with an elder attorney if anything is unclear.

POA will not let you put yourself as joint on an account. Both seniors will need to give the bank permission for you to be added. Like in person, signature required permission.

Being POA and joint account holder are two different things.

You should speak with the account holders and figure out the best path forward to protect the demented senior in the event they are the one left.