5 C.F.R. § 831.704
Annuities including credit for service with a nonappropriated fund instrumentality
(a) An annuity that includes credit for service with a nonappropriated fund instrumentality performed after December 31, 1965, based on an election under 5 CFR part 847, subpart D, is computed under 5 CFR part 847, subpart F.
(b) An annuity that includes credit for service with a nonappropriated fund instrumentality based on an election under 5 CFR part 847, subpart H, is computed under 5 CFR part 847, subpart I.