(a) The monthly survivor annuity benefit of an employee who elects to credit NAFI service under subpart H of this part will be subject to reduction.

(b) The reduction under paragraph (a) of this section equals:

(1) The difference in the present value of the initial survivor annuity generated from the immediate annuity computation with credit for NAFI service and the initial survivor annuity generated from the deferred annuity computation without credit for NAFI service, divided by

(2) The present value factor for the retiree's age (in full years) at the time of retirement.

(c) The present value of the survivor annuity generated from the immediate annuity with credit for NAFI service in paragraph (b)(1) of this section is computed under the provisions of § 847.905 of this subpart.

(d) The present value of the initial survivor annuity generated from the deferred annuity without credit for NAFI service in paragraph (b)(1) of this section is computed under the provisions of § 847.906 of this subpart.

(e) The ages of the employee as of the commencing date of the immediate retirement and the commencing date of the deferred retirement are used to compute the present value of the survivor benefits under paragraphs (c) and (d) of this section.