The U.S. has a "unified" gift and inheritance tax. If you give away $5M while you're alive and die with an estate of $5M you (1) pay no tax on gifts while aliv

The U.S. has a "unified" gift and inheritance tax. If you give away $5M while you're alive and die with an estate of $5M you (1) pay no tax on gifts while alive, and (2) your estate pays tax based on an estate size of $10M at the time of your death. There are a few wrinkles (e.g., (1) annual per-person exempt gifts of $14k/person, and (2) you do start paying tax on gifts while you're alive once total gifts pass a certain value), and gifting during lifetime has some advantages (e.g., getting growing assets out of your estate while they have a lower value), but that's generally the way it works. Gift tax and inheritance tax operate on a "unified" basis.