I not sure I understand. What you are telling me is that if the doner gives ever yr. then $13,000 is the limit. But the doner could do a one time deal of $5,120,000. is that correct?
So if they gift $5,000,000 and file the gift tax return and use the lifetime gift estate exclusion then not taxs are owed untill the doner dies.
how much is owed when the doner dies?