1.1016-10—Substituted basis.

(a) Whenever it appears that the basis of property in the hands of the taxpayer is a substituted basis, as defined in section 1016(b), the adjustments indicated in §§ 1.1016-1 to 1.1016-6, inclusive, shall be made after first making in respect of such substituted basis proper adjustments of a similar nature in respect of the period during which the property was held by the transferor, donor, or grantor, or during which the other property was held by the person for whom the basis is to be determined. In addition, whenever it appears that the basis of property in the hands of the taxpayer is a substituted basis, as defined in section 1016(b)(1), the adjustments indicated in §§ 1.1016-7 to 1.1016-9, inclusive, and in section 1017 shall also be made, whenever necessary, after first making in respect of such substituted basis a proper adjustment of a similar nature in respect of the period during which the property was held by the transferor, donor, or grantor. Similar rules shall also be applied in the case of a series of substituted bases.
(b) cation of this section may be illustrated by the following example:

Code of Federal Regulations

Example: A, who makes his returns upon the calendar year basis, in 1935 purchased the X Building and subsequently gave it to his son B. B exchanged the X Building for the Y Building in a tax-free exchange, and then gave the Y Building to his wife C. C, in determining the gain from the sale or disposition of the Y Building in 1954, is required to reduce the basis of the building by deductions for depreciation which were successively allowed (but not less than the amount allowable) to A and B upon the X Building and to B upon the Y Building, in addition to the deductions for depreciation allowed (but not less than the amount allowable) to herself during her ownership of the Y Building.
Code of Federal Regulations 77