Powers of Attorney in the United States are subject to the laws of individual states, so the document changes to conform to your particular state s laws. There is no overall federal law concerning Powers of Attorney, but there is a model Uniform Power of Attorney Act which many states have adopted, fully or partially.
You can name more than one attorney-in-fact if you believe that different people will better handle certain decisions or transactions. You may also name a fiduciary, such as an accountant, lawyer, or other professional as your attorney-in-fact if you wish.
Most states will recognize any POA that is validly signed in another state. So if you make a valid document while living in one state and then move to another state, your document will still be valid in your new state of residence. However, it may be a good opportunity to update your document and prevent it from being “stale”.
A Durable Power of Attorney also becomes effective immediately upon signing, however it allows the Agent to continue acting on behalf of the Principal even when he or she becomes incapacitated. This type ends automatically when you die, but you can also rescind it, as long you are not incapacitated.