What do you mean by "under it"? Are you saying that the amount is not in any box, but is below box 20? If that's what you mean, is there a code or abbreviation to the left (or right) of the amount? If so, what does it say? And what state did you work in? Is there anything in box 18 or 19? It sounds like your employer may have put something in a random place on the W-2 where it doesn't belong. They sometimes do that.