You decide when your power of attorney ends. If you have a durable power of attorney, the document can continue until your death. Because the document terminates when you die, the document can't give your attorney-in-fact authority to handle things after your death (e.g., paying debts, making funeral arrangements, or transferring property to heirs). These issues should be addressed in your last will or living trust.
Your durable power of attorney will also end if:
you revoke it. If you are mentally competent, you can revoke your durable power of attorney whenever you want.
a court invalidates it. This rarely happens, but a court can cancel your power of attorney if it finds that you were mentally incompetent when you signed it or that you were the victim of fraud or undue influence.
you get a divorce. In some states – including Alabama, California, Colorado, Illinois, Indiana, Minnesota, Missouri, Pennsylvania, Texas, and Wisconsin – a divorce automatically terminates a power of attorney if your ex-spouse was the attorney-in-fact under that document.