Most of the United States use post-mortem probate.  A person's will is submitted for probate after his or her death. 

The idea is that after the testator is dead, the will is read and the testator's estate is distributed in accordance with his wishes...

Life insurance and retirement plans compose the largest part of the estate for many people. Insurance death benefits, IRAs, Annuities, and 401(k)s do not pass under your will. They pass under contract law to those persons or organizations who are designated as the beneficiary...