There are many options you will have as you plan your estate in Pennsylvania. One of those options in a testamentary trust, which is a trust that is set up within your will, according to Yahoo! Finance. It is laid out and specified within the will. When you pass away, the assets indicated as part of the trust will go into the trust.
It is important to understand the point that the trust does not actually exist until you die. You have the ability to change it at any time, but once you die, it becomes irrevocable and cannot be changed by anyone else.