One question that arises for inventors is what will happen to their issued patent rights after their death. Determining who holds the rights to an issued patent after the inventor’s death depends on the actions taken, or not taken, during the inventor’s life.
Commonly, an inventor will assign their rights in their patented invention at some point during the application process, or shortly thereafter, to either their employer, a corporation, or another third-party. In this circumstance, the rights in the patent will be maintained as long as the assignment of rights has been reduced to writing and recorded with the U.S. Patent Office. 
Failure to put the assignment in writing will result in the assignment not being recognized. Failure to record the assignment can result in a subsequent purchaser or mortgagee supplanting the existing assignment as long as the new entity was not aware of the original assignment.
The rights in a patent can also be transferred by will or trust. The sufficiency of this form of transfer is governed by the applicable state law. 
If an inventor dies without a valid will, legally referred to as intestate, then state laws govern where the patent rights will transfer to. For instance, in Iowa, Iowa Code Sections 633.211 to 633.226 govern intestacy.
Based on a very basic outline of the Iowa intestacy rules the patent rights would first go to the inventor’s spouse, as long as there are no children from a previous relationship. If no spouse is present, or there are children from another relationship, the rights may be passed to the children or grandchildren. In the event that no children or spouses are present, the rights transfer to the parents. The rules of intestacy continue on to locate potential heirs and if none are found, the transfer ultimately goes to the state through what is known as escheat. For a more exhaustive explanation and guidance on the lineage of intestacy, consult a licensed attorney in your state.