In order to reflect gain recognized under section 1245(a)(1), the following adjustments to the basis of property shall be made:
Example: Jones exchanges property A, which is section 1245 property with an adjusted basis of $10,000, for property B, which has a fair market value of $9,000, and property C, which has a fair market value of $3,500, in a like kind exchange as to which no gain would be recognized under section 1031(a). Upon the exchange $2,500 gain is recognized under section 1245(a)(1), since property C is not section 1245 property. See section 1245(b)(4). Under the rules of section 1031(d), the basis of the properties received in the exchange is $12,500 (i.e., the basis of property transferred, $10,000, plus the amount of gain recognized, $2,500), of which the amount allocated to property C is $3,500 (the fair market value thereof), and the residue, $9,000, is allocated to property B.
26 C.F.R. §1.1245-5