Question
Why is it permissible to receive an organ donation, but not for a Jew to donate an organ?
Answer
Removing a vital organ from a person who is not yet legally dead (by halachic standards) is regarded as murder; but if the donor of the organ is already dead, or if removal of the organ isn’t fatal, it is meritorious to use the organ to save a life. It is permissible to accept organs that have already been harvested because the murder (if any) has already been done).