29 C.F.R. § 4044.52
Valuation of benefits.
CFR 2005 annual edition (revised as of 2005-07-01) · in effect Jul 1, 2000 to Jul 1, 2006 · last amended by 65 FR 14753, Mar. 17, 2000
The plan administrator shall value all benefits as of the valuation date by—
(a) Using the mortality assumptions prescribed by
§ 4044.53 and the interest assumptions prescribed in appendix B to this part;
(b) Using interpolation methods, where necessary, at least as accurate as linear interpolation;
(c) Using valuation formulas that accord with generally accepted actuarial principles and practices;
(d) Taking mortality into account during the deferral period of a deferred joint and survivor benefit only with respect to the participant (or other principal annuitant); and
(e) Adjusting the values to reflect loading expenses in accordance with appendix C to this part.