Are there any laws that disallow a person to be his mother's POA and beneficiary?

In answer to your question there is no contract that PNC is in breach of. You did not handle this correctly. Financial powers of attorney are for the living, not the dead. Your mother obviously did not have a properly drafted power of attorney drafted by a lawyer. Even where a lawyer drafts a power of attorney, the financial power of attorney is to be used to benefit the principal, in this case your mother. It is not to be used to benefit you. There are limits in power of attorneys as to whether an agent can make gifts to him or herself and even where permitted there may be a dollar limitation. Since you chose to rely on the PNC bank forms, you should have reviewed the form to see whether any sort of gift was authorized. My guess is that it was not. In such case you could not use the power of attorney to change the beneficiary on any IRAs or other beneficiary designated asset. Your mother had to do that. Making her estate the beneficiary, even by default, of an IRA was really poor estate planning. You have taken a non-probate asset which would be exempt from creditor's claims, and changed it to a probate one, exposing it to potential claims. Since the estate is beneficiary, there is going to be tax liability too. You or the personal representative of your mother's estate will need a probate attorney who practices in the county where your mother lived prior to her death. Pay the attorney to review the bank forms, insurance forms, any will and anything else of relevance. Without looking at this, I don't know if there is any way to salvage this absent probating an estate.