26 C.F.R. § 1.358-5
Special rules for assumption of liabilities
(a) In general. Section 358(h)(2)(B) does not apply to an exchange occurring on or after May 9, 2008.
(b) Effective/Applicability date. For exchanges occurring on or after June 24, 2003, and before May 9, 2008, see § 1.358-5T as contained in 26 CFR part 1 in effect on April 1, 2007.