Prenuptial Agreement Oregon: Rules, Validity, and Cost

You and your partner are building a life in Oregon. Maybe that means a house together in Portland, a small business one of you started before you met, or student debt you would rather not blur into one shared pile. Before the wedding, a lot of couples find themselves wondering how the state would sort all of that out if things ever changed, and whether they can decide those terms themselves instead. According to CDC/NCHS provisional 2023 data, the U.S. divorce rate was 2.4 per 1,000 people, a reminder that planning for the unexpected is a normal part of building something together, not a sign of doubt.

A prenuptial agreement, commonly called a prenup, is one way Oregon couples decide their own terms in advance. Oregon law recognizes these agreements, and it also sets specific rules for what makes one hold up. Here is what couples in Oregon should know before saying "I do."

Is a prenup valid in Oregon?

Yes. Oregon adopted the Uniform Premarital Agreement Act, a model law written by the Uniform Law Commission and adopted by 29 states plus the District of Columbia to bring consistency to how premarital agreements are treated. In Oregon, it is codified at ORS 108.700 to 108.740.

Under that framework, a premarital agreement in Oregon must be in writing and signed by both parties. It becomes effective upon marriage. No court filing is required for it to be valid, and you do not attach it to your marriage license. Oregon is one of many states where prenups are governed by this shared model law, though the details vary from state to state. Our state-by-state guide walks through how the rules differ.

The practical takeaway: a prenup is a private contract between you and your partner. You keep it, and you provide it if a dispute ever arises.

How does Oregon divide property without a prenup?

Here is where a common misconception trips people up. Oregon is not a community property state. It is an equitable-distribution state under ORS 107.105(1)(f), which means a court divides marital property based on what is just and proper, and "equitable" does not always mean "equal."

In a community property state, most assets acquired during marriage are split down the middle by default. Oregon works differently. A judge looks at the full picture and divides property by what the court considers fair given the circumstances. Oregon law does apply a rebuttable presumption that both spouses contributed equally to marital property, but that presumption can be overcome, and the final split rests on the judge's discretion. If you want to understand the contrast in more detail, our guide to community property states lays it out.

One Oregon quirk surprises a lot of couples: the court may reach even assets one partner owned before the marriage or holds in their own name alone. Separate title does not always keep an asset out of the division. That is one reason many Oregon couples decide to put their intentions in writing ahead of time rather than leave the question to a judge later.

What makes an Oregon prenup enforceable?

Oregon does not enforce every prenup automatically. Under ORS 108.725, a premarital agreement can be found unenforceable in two main situations.

The first is voluntariness. If the party challenging the agreement proves they did not sign it voluntarily, a court can decline to enforce it. Oregon case law has treated voluntariness as meaning the signer understood what they were agreeing to and was free from coercion. In Rudder and Rudder, 230 Or App 437 (2009), the Oregon Court of Appeals examined what it means for a party to enter an agreement knowingly and without pressure.

The second is unconscionability combined with a lack of disclosure. An agreement that was unconscionable when signed, meaning so one-sided or unfair at the time that a court may decline to enforce it, can be set aside if the challenging party was not given fair disclosure of the other's finances and could not reasonably have known them on their own. This is why full financial disclosure matters so much. When both partners lay their finances on the table, they remove one of the main grounds a court would use to throw the agreement out. Our piece on why full financial disclosure matters explains the how and the why.

For a broader look at the elements that hold a prenup together, see what makes a prenup enforceable. A well-drafted Oregon prenup is designed to satisfy each of these requirements from the start.

What can an Oregon prenup cover?

A prenup gives you room to decide a lot, and it has clear limits.

On the "can" side, an Oregon prenup can address how you handle property acquired during the marriage, how you treat property either of you owned before it, how you assign responsibility for debt, and how you approach spousal support. Instead of leaving these questions to a judge's discretion, you and your partner define them together in advance.

Spousal support deserves a careful note. An Oregon prenup can address spousal support, and a waiver is not absolute. Oregon case law has recognized that a support waiver may not be enforced if it would leave a spouse without necessary support they cannot obtain elsewhere. The court in Bridge and Bridge, 166 Or App 458 (2000) addressed this kind of limit. So while you can shape support terms, you cannot count on a blanket waiver holding up in every circumstance. Our overview of spousal support covers the concept in plain terms.

On the "cannot" side, the line is bright. Under ORS 108.710, a premarital agreement cannot adversely affect a child's right to support. Oregon courts decide custody, parenting time, and child support based on the child's best interests at the time of the dispute, regardless of what a prenup says. Those questions belong to the court, not to a contract.

Here is how the default rules and a prenup compare, dimension by dimension.

How do you get a prenup in Oregon?

The mechanics are more approachable than most couples expect. A few practical steps make the process smoother.

Start early. Under ORS 108.715, an Oregon prenup becomes effective upon marriage, so it needs to be signed before the wedding. Giving yourselves a comfortable runway ahead of the date reduces any argument later that someone felt rushed or pressured, which ties back to the voluntariness requirement.

Have the disclosure conversation. Because fair financial disclosure is central to enforceability in Oregon, both partners should share a full picture of what they own and what they owe. Think assets, income, and debts. This conversation tends to be less awkward than couples fear, and it often opens up a useful discussion about money, goals, and how you want to build your life together.

Put it in writing and sign it. The agreement must be written and signed by both parties. Many couples also choose to have independent legal review, where each partner has their own set of eyes on the document, which further supports the voluntariness and understanding that Oregon courts look for.

Consider the cost realistically. Prenup pricing varies with complexity and the path you choose. Our guide to how much a prenup costs breaks down what shapes the price so you can plan.

Frequently asked questions

Is Oregon a community property state?

No. Oregon is an equitable-distribution state under ORS 107.105(1)(f), which means a court divides marital property based on what is just and proper, not an automatic 50/50 split. Fair does not always mean equal, so outcomes vary. A prenup lets a couple set their own terms instead.

Are prenuptial agreements legal in Oregon?

Yes. Oregon adopted the Uniform Premarital Agreement Act, codified at ORS 108.700 to 108.740. A premarital agreement must be in writing and signed by both parties, and it becomes effective upon marriage. No court filing is required for it to be valid, so it works as a private contract between you and your partner.

What makes a prenup unenforceable in Oregon?

Under ORS 108.725, a prenup is not enforceable if the challenging party proves they did not sign voluntarily, or that the agreement was unconscionable when signed and they were not given fair disclosure of the other party's finances and could not reasonably have known them on their own.

Can an Oregon prenup waive spousal support?

An Oregon prenup can address spousal support, but a waiver may not be enforced if it would leave a spouse without necessary support they cannot obtain elsewhere. Oregon case law has recognized this limit, so a support waiver is not absolute and depends on the circumstances at the time of a dispute.

Does a prenup have to be filed with a court in Oregon?

No. An Oregon prenup is a private contract that becomes effective upon marriage; it is not filed with a court or attached to your marriage license to be valid. You keep it yourself and provide it if a dispute ever arises down the road.

Can a prenup decide child custody or child support in Oregon?

No. Under ORS 108.710, a premarital agreement cannot adversely affect a child's right to support. Oregon courts decide custody, parenting time, and child support based on the child's best interests at the time, regardless of what a prenup says about those questions.

Getting started with First in Oregon

If you and your partner are building a life in Oregon, a prenup is one way to decide your own terms together instead of leaving them to a judge later. No hourly billing, no piles of paperwork, no back and forth with attorneys before you are ready. First offers a fully digital way to create a prenup on your timeline, with the Self-Serve, Lawyer Review, and Bespoke packages. When the timing feels right, you can start whenever you and your partner are ready.

Oregon rules and figures can change over time, and couples with complex assets or businesses may want independent legal counsel to review their situation. Everything here is meant as what couples in Oregon should know, not legal advice for your specific circumstances.

Methodology

These figures are drawn from CDC/NCHS National Vital Statistics System data on marriages and divorces, covering the most recent provisional and final years available (national provisional 2023), based on records reported by state health departments. Statute references are drawn from the Oregon Revised Statutes as published by the Oregon State Legislature.

Sources

First is not a law firm. The information and tools provided by First on this site are not legal advice and not a substitute for the advice of an attorney.