26 U.S. Code§ 1.1031(c)-1 Nonrecognition of loss.
Section 1031(c) provides that a loss shall not be recognized from an exchange of property described in section 1031(a), 1035(a), 1036(a), or 1037(a) where there is received in the exchange other property or money in addition to property permitted to be received without recognition of gain or loss. See example (4) of paragraph (a)(3) of § 1.1037-1 for an illustration of the application of this section in the case of an exchange of U.S. obligations described in section 1037(a).