5 CFR § 837.702 - Offset from supplemental survivor annuity.
(a) OPM will reduce a supplemental survivor annuity (an annuity under 5 U.S.C. 8341) based on the service of an individual who performed CSRS-Offset service, if the survivor annuitant is entitled, or on proper application would be entitled, to survivor benefits under section 202(d), (e), or (f) (relating to children's, widows', and widowers' benefits, respectively) of the Social Security Act.
(b) The reduction required under paragraph (a) of this section begins (or is reinstated) on the first day of the month during which the survivor annuitant—
(1) Is entitled to a disability or survivor annuity under CSRS; and
(2) Is entitled, or on proper application would be entitled, to survivor benefits under the Social Security Act provisions mentioned in paragraphs (a) and (c) of this section, respectively.
(c) The reduction under paragraphs (a) of this section will be computed and adjusted in a manner consistent with the provisions of § 837.701 (c) through (e) of this part.
(d) A reduction under paragraph (a) of this section stops on the date entitlement to the disability or survivor benefits under title II of the Social Security Act terminates. In the case of a survivor annuitant who has not made proper application for the social security benefit, the reduction under paragraph (a) of this section stops on the date entitlement to such survivor benefits would otherwise terminate. If a social security benefit is reduced under any provision of the Social Security Act, even if reduced to zero, entitlement to that benefit is not considered to have terminated.
(e) OPM will accept the determination or certification of the Social Security Administration, submitted in a form prescribed by OPM, concerning entitlement to social security survivor benefits and the beginning and ending dates thereof.