As long as you’re considered mentally capable of doing, You can revoke your medical power of attorney at any time. If you wish to revoke your POA, you can fill out a revocation of power of attorney form. You need to have it witnessed and notarized. This form will mention that you no longer want your chosen agent to act as your medical POA. At any point of time, you can create a new medical POA agreement and name a new healthcare agent, or change your current agent’s responsibilities.