My uncle is going to try and steal all my grandmas money.

Does grandma have a will? Once she dies, uncle's power of attorney ends. The person who will have control over distributing her estate will be the executor named in her will, and if there's no will it will be a representative appointed by the court. Your uncle may put himself forward to be the representative, but someone else in the family can argue it should be them instead. In a small estate like 17k, most states have a short cut procedure you can use. But if there's a dispute among the family, it maybe better to do a full probate case so things are more formal. If it can be shown that uncle withdrew a lot of money right before she died, it may be possible to claw that back to be part of the estate -- you would need a lawyer's advice on the specifics.

As long as she is living, you (or an appropriate family member) would have to hire a lawyer and go to court and prove he has misused the poa to get it revoked.

You should let the bank(s) know as soon as she dies, so they know your uncle no longer has authority to withdraw funds.

/r/legaladvice Thread