Sections 1.617-3 and 1.617-4 apply on and after January 19, 2017. For rules before January 19, 2017, see §§ 1.617-3 and 1.617-4 as contained in 26 CFR part 1 revised as of April 1, 2016.

[T.D. 9811, 82 FR 6239, Jan. 19, 2017]