Gift tax

In 1999 I have given stock worth $9,000 to a friend.It has now appreciated to $21,000.He is going to transfer it back to me. Does he have to file a gift tax return for 2000. Both of us are US residents.
thank you.

The law is that if the gift (and all other gifts to the person) during the calendar year is less than $10,000 ($20,000 if your spouse joined in the gift) no gift tax return is due.

If there is a gift back, same thing. There may not be a tax to pay, just a return to file, and to the extent it exceeds $10,000 (or $20,000) it eats in to the lifetime exemption. There is no exception that I am aware of for gifts back and forth.