How Do Prenups Affect Inheritance Rights?

A prenuptial agreement does not just decide who gets what in a divorce. It can also reshape what a surviving spouse receives when the other spouse dies, sometimes dramatically.

For related help, see divorce help, prenuptial-agreement guide, and property-division guide.

The Rights a Spouse Has at Death

When someone dies in Washington, their surviving spouse usually holds a strong claim to a share of the estate. That claim comes from two directions. The first is community property. Property that a married couple acquires during the marriage is generally community property, and each spouse owns an undivided one-half interest in it. Washington law defines community property and limits what one spouse can do with it by will, providing that neither spouse may give away by will more than one-half of the community property. See RCW 26.16.030. In plain terms, you can only will away your own half of the community estate, and your spouse's half already belongs to your spouse.

The second source of protection is Washington's intestacy scheme, which controls when a person dies without a valid will. Under RCW 11.04.015, a surviving spouse receives all of the decedent's share of the net community estate, plus a portion of the separate estate that ranges from one-half to all of it depending on who else survives the decedent. If the deceased spouse left children, the surviving spouse takes half of the separate property. If there are no children but a surviving parent or sibling, the surviving spouse takes three-quarters. If there is no surviving issue, parent, or issue of a parent, the surviving spouse takes all of the separate estate. These default rules give a surviving spouse a meaningful stake in the estate even where there is no will directing anything to them.

How a Prenup Changes the Picture

A prenuptial agreement can alter both of these default protections by changing how property is characterized and by including waivers of the rights a spouse would otherwise have at death. Two people can agree, before they marry, that certain assets will remain each person's separate property rather than becoming community property. Because the community property limits and the intestate shares in RCW 26.16.030 and RCW 11.04.015 depend on whether property is community or separate, changing that characterization changes what flows to the survivor. If assets that would otherwise have been community property are instead kept separate under the agreement, the surviving spouse's automatic one-half community interest in those assets does not attach.

A prenup can go further and include an express waiver, where each party gives up the claims they would otherwise be able to assert against the other's estate. A spouse can agree in advance to waive the share they would receive under the intestacy statute, or to accept a fixed amount, or to take nothing from certain accounts or property. This is common in second marriages, where one or both spouses want to make sure specific assets pass to children from a prior relationship rather than to the new spouse. Done properly, the agreement lets each person plan around the default rules instead of being bound by them.

Why the Agreement Has to Be Fair to Hold Up

None of this works if the agreement is not enforceable. Washington has no single statute that governs when a prenuptial agreement is valid, so the rules come from court decisions. The leading case is In re Marriage of Matson, 107 Wn.2d 479 (1986), which set out a two-part test. A court first asks whether the agreement made a fair and reasonable provision for the spouse who is not seeking to enforce it. If it did, the agreement can stand on that basis alone. If it did not, the court moves to the second question and examines the fairness of the process: whether both parties fully disclosed their assets, whether each understood the rights they were giving up, whether each had the chance for independent legal advice, and whether the agreement was signed freely rather than under pressure.

That second prong matters enormously for inheritance waivers, because a spouse who signs away a claim to an estate is giving up something significant. If the surviving spouse can later show that they never received full disclosure of what the deceased spouse actually owned, or that they were rushed into signing without a real chance to understand the consequences, a court may decline to enforce the waiver. When that happens, the default rules in RCW 26.16.030 and RCW 11.04.015 can come back into play, and the surviving spouse may recover a share the agreement was written to prevent.

Coordinating the Prenup With the Rest of the Estate Plan

A prenup is one piece of a larger plan, not the whole plan. For the agreement to do its job at death, the will, any trusts, and the beneficiary designations on accounts should line up with what the prenup says. An agreement that keeps an account separate accomplishes little if the account still names the spouse as beneficiary and no one updates it. Some assets, including certain retirement plans governed by federal law, carry their own rules about spousal rights that a prenup alone may not override, which is one more reason to treat the agreement as part of a coordinated plan rather than a standalone fix.

For families in Snohomish County thinking about a second marriage, a blended family, or simply wanting certainty about how assets will pass, this is worth getting right the first time. If you are weighing how a prenuptial agreement could protect your children, your business, or your estate, the Law Office of Chad Foster is here to talk through your options and help you build an agreement that holds up when it matters.