In those cases, the value applicable in determining the basis of the property is not the value at the date of the decedent's death but (with certain limitations) the value at the date one year after his death if not distributed, sold, exchanged, or otherwise disposed of in the meantime. If such property was distributed, sold, exchanged, or otherwise disposed of within one year after the date of the decedent's death by the person who acquired it from the decedent, the value applicable in determining the basis is its value as of the date of such distribution, sale, exchange, or other disposition. For illustrations of the operation of this paragraph, see the estate tax regulations under section 2032.
26 C.F.R. §1.1014-3