You first need to tell us if it is real estate, or non-real estate. The rules differ.
As the other comments mentioned, there is often "recapture" when an asset is sold (when the selling price of non-real-estate is higher than the Adjusted Basis). But in some cases there can be different kinds of "recapture" BEFORE an asset is sold (such as when you use Section 179 or if you are talking about "Listed Property", such as a vehicle).
Because the rules can be very complex, it is almost impossible to give you a complete answer unless we know exactly what kind of asset you are talking about, and what kind of depreciation has been taken.
