If I give my son stock as a gift today, will his basis be my basis?

If I give my son stock as a gift today, will his basis be my basis? How does he determine the date of purchase when he wants to sell the stock? Is it the date when I purchased the stock or the date when I transfer the stock to him?

There are two basis rules for gifts. One rule is for gifts made during your lifetime, and the other applies to bequests or gifts made at death. Assets transferred after death come with a "stepped-up" basis, or whatever the fair market value is. When you make a gift during your lifetime, the recipient steps into your shoes. That means that your son's basis is your basis and the date of purchase is your purchase date.