26 CFR § 20.7520-1
General actuarial valuations.
(1) Except as otherwise provided in this section and in § 20.7520-3 (relating to exceptions to the use of prescribed tables under certain circumstances), in the case of estates of decedents with valuation dates after April 30, 1989, the fair market value of annuities, interests for life or for a term of years (including unitrust interests), remainders, and reversions is their present value determined under this section. See § 20.2031-7(d) (and, for periods prior to May 1, 2009, § 20.2031-7A) for the computation of the value of annuities, unitrust interests, life estates, terms for years, remainders, and reversions, other than interests described in paragraphs (a)(2) and (a)(3) of this section.
(2) In the case of a transfer to a pooled income fund, see § 1.642(c)-6(e) of this chapter (or, for periods prior to May 1, 2009, § 1.642(c)-6A) with respect to the valuation of the remainder interest.
(3) In the case of a transfer to a charitable remainder annuity trust with a valuation date after April 30, 1989, see § 1.664-2 of this chapter with respect to the valuation of the remainder interest. See § 1.664-4 of this chapter with respect to the valuation of the remainder interest in property transferred to a charitable remainder unitrust.