45 U.S.C. § 231j

Any person awarded an annuity under this subchapter may decline to accept all or any part of such annuity by a waiver signed and filed with the Board. Such a waiver may be revoked in writing at any time, but no payment of the annuity waived shall be made covering the period during which such waiver was in effect. Such a waiver will have no effect on entitlement to, or the amount of, any other annuity or benefit.