Oregon Revised Statutes Probate Law § 114.620

(1) The right of election under ORS 114.600 to 114.725 may be waived, wholly or partially, before or after marriage by a written contract, agreement or waiver signed by the surviving spouse.

(2) Unless specifically provided otherwise, a written agreement that waives all rights in the property or estate of a present or prospective spouse, using the phrase “all rights” or other equivalent language, or a complete property settlement entered into after or in anticipation of separation or divorce is a waiver of all rights to an elective share under ORS 114.600 to 114.725 by each spouse in the property of the other and a renunciation by each of all benefits that would otherwise pass to each spouse from the other by intestate succession or by virtue of any will executed before the written agreement or property settlement.