What constitutes legal capacity for purposes of granting power of attorney? My grandfather was recently in a car accident and is in the hospital. He wants to give my mother power of attorney so she can pay his bills and handle legal matters on his behalf surrounding the accident. He has the mental capacity to grant power of attorney (to which his doctors agreed) but he is physically unable to sign; he cannot even hold a pen to draw a line. If he has the mental capacity to understand his actions, does he need the physical ability to sign. He fractured his neck and cannot hold a pen in his mouth either. Unfortunately, no one has the money to go through the guardianship procedure (we were told by an attorney that it costs $6500) or to pay his bills in the interim without accessing his account where his modest social security income is directly deposited. Any guidance you can offer is appreciated.