Wyoming Prenuptial Agreement Laws: Enforceability and Case Law (2026)

Prenuptial agreements can be enforced in Wyoming, but no premarital-agreement act appears in Wyoming's family-law title, Title 20 of the Wyoming Statutes. In Jones v. Young, 2025 WY 130, the Wyoming Supreme Court said that marital agreements, whether prenuptial or postnuptial, are valid and enforceable in Wyoming and are governed by the same rules of construction as other contracts. An older decision, Laird v. Laird, 597 P.2d 463 (Wyo. 1979), upheld an antenuptial agreement against claims of fraud, overreaching and nondisclosure on the facts of that case.

Information last verified on 2026-10-09. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers how Wyoming treats premarital (prenuptial or antenuptial) agreements under Wyoming Supreme Court decisions, including Jones v. Young (2025) and Laird v. Laird (1979), the writing and waiver rules in Wyoming Statutes §§ 1-23-105 and 2-5-102, and the property-division rule in § 20-2-114. It does not cover spousal-support waivers, child support or custody terms, or other states' law. For how property is divided without an agreement, see Wyoming divorce laws.

Are prenups enforceable in Wyoming?

Yes. In Jones v. Young, 2025 WY 130, the Wyoming Supreme Court said: "Marital agreements, whether prenuptial or postnuptial, are valid and enforceable in Wyoming and are governed by the same rules of construction applicable to other contracts." The court repeated that statement in Smerski v. Lemon, 2026 WY 61, a 2026 case interpreting a postnuptial agreement.

Earlier decisions also enforced these agreements. In Laird v. Laird, 597 P.2d 463 (Wyo. 1979), the Wyoming Supreme Court affirmed a partial summary judgment that upheld an antenuptial agreement against a husband's claims of fraud, overreaching, lack of understanding and nondisclosure. The court decided that case on its particular facts and the issues presented.

The court described the case this way:

"This case is concerned with the propriety of granting a motion for partial summary judgment where the validity of an antenuptial contract is challenged on the basis of fraud, deceit, overreaching, lack of understanding, and failure to make a complete disclosure of assets."

Which Wyoming law governs a prenup?

No premarital-agreement act appears in Title 20 of the Wyoming Statutes. Title 20 is organized into chapters on husband and wife (including creation of marriage and spouses' rights and liabilities), dissolution of marriage, desertion, interstate family support, child custody, child support enforcement, visitation and child abduction prevention. None of those chapters sets rules for premarital agreements.

Wyoming's prenup rules come from Wyoming Supreme Court decisions such as Jones and Laird, and from two general statutes outside Title 20.

Writing and signature requirements

Wyoming's statute of frauds, W.S. 1-23-105(a)(iii), makes void "Every agreement, promise or undertaking made upon consideration of marriage, except mutual promise to marry" unless the agreement, or some note or memorandum of it, is in writing and "subscribed by the party to be charged therewith."

Wyoming's probate code adds a rule for inheritance rights. Under W.S. 2-5-102, a spouse's right of election and rights to homestead allowance, exempt property and family allowance "may be waived totally or partially before or after marriage, by a written contract, agreement or waiver signed by the party waiving, after fair disclosure."

A Wyoming lawyer can explain which formalities apply to a specific agreement.

Disclosure, fraud and overreaching

The challenges in Laird show what a party may argue to defeat an agreement: fraud, deceit, overreaching, lack of understanding, and failure to make a complete disclosure of assets.

On disclosure, Laird relied on In re Estate of Borton, 393 P.2d 808 (Wyo. 1964), describing it as holding "that the mere fact that detailed disclosure was not made will not necessarily void an otherwise properly executed antenuptial contract. It is not necessary that the complaining spouse be furnished with a financial statement of net worth and income." In Laird itself, the husband knew before the wedding that his future wife had substantial wealth.

A footnote in Laird notes that Borton had cited with acceptance a Kansas decision, In re Ward's Estate, 285 P.2d 1081 (Kan.). That decision accepted the general rule that there must be a fair disclosure of assets, then set its limits:

"where it appears an antenuptial contract was understandingly made and freely executed, and where there is an absence of anything showing fraud or deceit, the mere fact the intended husband did not disclose in detail to the intended wife the nature, extent and value of his property will not, of itself, invalidate the contract or raise a presumption of fraudulent concealment"

Laird also rejected the argument that an antenuptial contract must be examined with close scrutiny, saying the court would "review the antenuptial contract much as we would any other contract." It held that a husband who was able to read the agreement, and had the opportunity to do so, could not avoid it because he read only part of it.

This page does not cover other enforceability questions, such as timing before the wedding, waivers of spousal support, terms about children, or how an agreement is amended or revoked. A lawyer licensed in Wyoming can explain how those issues apply to a specific agreement.

Property division without a prenup

Without an enforceable agreement, a Wyoming divorce court divides property under W.S. 20-2-114(a). That section directs the court to "make such disposition of the property of the parties as appears just and equitable, having regard for the respective merits of the parties and the condition in which they will be left by the divorce," along with the party through whom the property was acquired and the burdens imposed on the property for the benefit of either party and children. For more on that process, see Wyoming divorce laws, and for spousal support, see Wyoming alimony laws.

Postnuptial agreements

An agreement signed after the wedding is a postnuptial agreement. In Jones v. Young, 2025 WY 130, the couple signed a postnuptial agreement two days after the wedding, and the Wyoming Supreme Court upheld the ruling that it was enforceable. The court said "a postnuptial agreement must be supported by consideration and the marriage itself cannot provide that consideration." In that case, the spouses' mutual promises to give up rights in each other's premarital property and their statutory elective shares were adequate consideration.

Jones also applied Wyoming's two-part test for unconscionability: "both the absence of meaningful choice and the presence of contract provisions unreasonably favorable to one party must be found in order to sustain a claim that a contract is unconscionable." The husband's lawyer drafted the agreement, and the wife did not consult her own lawyer. The agreement stated that she had been advised to seek advice from an attorney of her choosing, and the court held that her conclusory claim that she had no opportunity to consult a lawyer did not create a factual dispute on procedural unconscionability.

Disclaimer: This article provides general legal information about premarital agreements in Wyoming, based on Wyoming Supreme Court decisions and the Wyoming Statutes, verified on 2026-10-09. It is not legal advice. For advice about a specific agreement, consult a lawyer licensed in Wyoming.

Related

• Prenuptial agreement laws in every state
• Wyoming divorce laws
• Wyoming alimony laws

Last updated: 2026-10-09.

Frequently Asked Questions

Does Wyoming have a prenuptial agreement statute?

No premarital-agreement act appears in Title 20 of the Wyoming Statutes, the family-law title. Two general statutes apply: under W.S. 1-23-105(a)(iii), an agreement made upon consideration of marriage is void unless it is in writing and signed by the party to be charged, and under W.S. 2-5-102 a spouse can waive the elective share and related allowances before marriage only by a signed written agreement made after fair disclosure. The other rules come from Wyoming Supreme Court decisions such as Jones v. Young (2025) and Laird v. Laird (1979).

Will a Wyoming court enforce a prenup?

Yes. In Jones v. Young, 2025 WY 130, the Wyoming Supreme Court said that marital agreements, whether prenuptial or postnuptial, are valid and enforceable in Wyoming and are governed by the same rules of construction as other contracts. Earlier, in Laird v. Laird (1979), it affirmed a partial summary judgment upholding an antenuptial agreement against claims of fraud, overreaching, lack of understanding and nondisclosure.

Does a Wyoming prenup require full financial disclosure?

Laird relied on In re Estate of Borton (Wyo. 1964), which held that the mere fact that detailed disclosure was not made will not necessarily void an otherwise properly executed antenuptial contract, and that a financial statement of net worth and income is not required. Separately, W.S. 2-5-102 allows a waiver of the elective share and related allowances only after fair disclosure.

How is property divided in Wyoming without a prenup?

Under W.S. 20-2-114(a), the divorce court makes a disposition of the parties' property that appears just and equitable, considering the respective merits of the parties, the condition in which the divorce leaves them, the party through whom the property was acquired and the burdens imposed on the property for the benefit of either party and children.