Section 847.421 - Election requirements(a)(1)(i) A FERS employee who completed a qualifying move under § 847.402(b) may, instead of the election provided by § 847.441 (pertaining to elections of NAFI retirement coverage), elect to remain subject to FERS for all subsequent periods of service.(ii) Prior service under a NAFI retirement system becomes creditable under FERS rules without regard to whether a refund of contributions for such period has been paid by the NAFI retirement system.(2) A FERS employee who has had a previous opportunity to elect retirement coverage under § 847.202(e) or (f) is not excluded from making this election.(b) A survivor may make an election under paragraph (a) of this section if the employee was otherwise eligible to elect FERS coverage and FERS service credit, but died before expiration of the time limit under § 847.304 .(c) NAFI service made creditable under FERS by an election under this section become creditable for FERS retirement eligibility and FERS annuity computation, including average pay, upon receipt of the election by the employing agency.(d) A election under this section is irrevocable when received by the employing agency.61 FR 41721, Aug. 9, 1996, as amended at 68 FR 2180 , Jan. 16, 2003