Living donation is completely voluntary. Being a registered organ donor does not mean you will be called to give an organ while living.
There are two transplant hospitals in the state of Kentucky that have a living donation program: Jewish Hospital in Louisville and University of Kentucky Hospital in Lexington. The two most commonly used organs for living donation are the kidney and liver. You only need one kidney in order to live and the liver regenerates (grows back) which makes this type of donation possible.