You signed a prenuptial agreement before your marriage. Now that divorce is on the table, one of you is wondering whether the agreement can be thrown out.
The short answer is yes, but “can be” and “usually are” describe two different realities. Michigan courts favor enforcing prenups, and the challenger carries the burden of proof. There is also a second answer most people never hear: a few provisions are unenforceable no matter how carefully the agreement was drafted or how freely it was signed.
The Michigan Framework
Michigan has no single prenuptial agreement statute. Enforceability rests on two statutes and a line of cases.
MCL 557.28 provides that a contract relating to property made between persons in contemplation of marriage remains in full force after the marriage takes place. The Statute of Frauds, MCL 566.132(1)(c), makes an agreement made upon consideration of marriage void unless it is in writing and signed by the party to be charged.
The landmark case is Rinvelt v Rinvelt, 190 Mich App 372 (1991), which held that antenuptial agreements governing the division of property on divorce are enforceable in Michigan. Rinvelt also adopted the three questions Michigan courts still ask:
- Was the agreement obtained through fraud, duress or mistake, or misrepresentation or nondisclosure of material fact?
- Was the agreement unconscionable when it was executed?
- Have the facts and circumstances changed since execution so as to make enforcement unfair and unreasonable?
If none of those is present, the agreement stands. And the party attacking it “bears the burden of proof and persuasion.” Reed v Reed, 265 Mich App 131 (2005).
Ground One: Duress
The most common attack is that the agreement was not signed voluntarily. It is also the hardest to win, because Michigan requires unlawful coercion, not pressure. A fiancé who says the wedding is off without a signed agreement is making a lawful demand, however unwelcome.
Consider Allard v Allard, where the parties signed two days before the wedding. That is the fact pattern people assume is fatal, and the agreement was not set aside on duress grounds. Timing, inequality of bargaining power, language barriers, and financial sophistication all matter to the analysis, but “I felt pressured” is not a ground. Courts want evidence of coercion that was itself wrongful.
Ground Two: Nondisclosure, and the Presumption That Can Shift the Work
This is the ground that actually moves cases, because Michigan imposes a heightened duty here. Antenuptial agreements “give rise to a special duty of disclosure not required in ordinary contract relationships.” In re Estate of Benker, 416 Mich 681 (1982).
Prenup challenges are rarely won on the terms. They are won on the disclosure nobody finished documenting.
Benker did more than state a duty. While the challenger still carries the burden, a rebuttable presumption of nondisclosure can arise from a combination of facts: a complete waiver leaving the spouse nothing, a wide disparity in estates, a secretive spouse whose modest living concealed real wealth, no disclosure recital in the agreement, and no independent counsel. Once that presumption is raised, the party defending the agreement must come forward with evidence to rebut it.
Two limits matter. A lopsided split alone does not raise the presumption; the Court said so expressly. And Benker was a probate case about a widow’s rights at death, so in a divorce its presumption reasoning is persuasive rather than binding. What carries over cleanly is the duty itself, which is also the first Rinvelt factor.
Ground Three: Unconscionability and Changed Circumstances
Unconscionability is measured at execution. A bargain that favors one side is not unconscionable; adults are allowed to make lopsided deals.
The changed-circumstances attack is the one people most often misjudge, because Michigan gates it with foreseeability. For a change to count, the event “must not have been reasonably foreseen by the parties prior to or at the time of the making of the agreement.” In Reed, a spouse’s separate estate grew from under $20,000 to more than $5 million across a marriage of more than two decades, and the Court of Appeals reversed the trial court for setting the prenup aside. Having agreed to be “captains of their own financial ships,” the parties could foresee that separate assets would grow, and grow at different rates.
Ground Four: The Document Itself
The simplest vulnerabilities are in the paperwork. Because the Statute of Frauds applies, an oral understanding about property has no effect at all. Missing signatures, unexecuted drafts, and genuinely ambiguous terms are all real openings. Notarization, on the other hand, is not required.
Some Prenup Provisions Cannot Be Enforced No Matter How They Are Written
Everything above is about attacking an agreement. This is different. A small category of clauses fails on its own, even inside an agreement that was fully disclosed, freely signed, and fair on its face. The clause does not void the rest of the prenup. It simply does not do what it appears to do.
The clauses that fail are the ones that try to limit what a divorce judge is allowed to do.
Two Michigan statutes give a divorce court authority the spouses cannot contract away. MCL 552.23(1) lets a judge award support out of one spouse’s separate property when what each side receives in the divorce is not enough for that person’s suitable support, or the support of any children of the marriage in that person’s care. MCL 552.401 lets a judge award one spouse part of property titled to the other, where the first spouse contributed to acquiring, improving, or accumulating it.
In Allard v Allard, 318 Mich App 583 (2017), the Court of Appeals explained why a prenup cannot switch either one off. Those statutes hand power to the court. They do not hand rights to the spouses, and a person cannot waive a right she never held.
The practical effect is narrower than it sounds. A spousal support waiver is still proper subject matter for a prenup, and Allard said so directly. In most divorces the waiver is honored, because each side leaves with enough and the judge has no reason to look further. It matters at the margin: where one spouse would otherwise walk out of the marriage unable to support herself or the children in her care, the court keeps the power to reach separate property no matter how the agreement is worded.
If you were told your agreement was bulletproof, this is the part that got left out. It is not a drafting mistake, and it is not a reason to skip a prenup. It is the outer limit of what any Michigan prenup can do.
Frequently Asked Questions About Challenging a Prenup in Michigan
Yes. A Michigan court can set aside a prenuptial agreement on the following grounds: fraud, duress, mistake, misrepresentation or nondisclosure of a material fact; unconscionability at the time it was executed; or circumstances that changed unforeseeably so that enforcement would now be unfair. The challenger carries the burden of proof. Separately, a clause limiting the court’s equitable powers is void whether or not the rest of the agreement survives.
No. Michigan has not enacted it. Senate Bill 160 would create a Michigan version and passed the Senate on May 7, 2025, but it has been sitting in the House Judiciary Committee since and is not law. Enforceability is still governed by MCL 557.28, the Statute of Frauds, and case law.
Yes, but the waiver does not bind the judge. A spousal support clause is proper subject matter for a Michigan prenup. What it cannot do is remove the court’s authority under MCL 552.23(1) to award support out of a spouse’s estate where it is needed. After Allard, a waiver may be honored in practice and still leave the court free to act. See our guide to what Michigan courts actually consider in awarding alimony.
No, not as a legal requirement. Michigan has no rule that a person be represented before signing a binding contract, and under Reed the absence of counsel is not by itself a reason to refuse enforcement. But it is one of the facts that can help raise a presumption of nondisclosure, which makes it one of the cheapest protections available.
Talk to a Michigan Family Law Attorney
A prenup challenge means discovery, financial records, depositions, and contested hearings, and the outcome usually turns on choices made years earlier: whether disclosure was documented, whether both sides had counsel, whether the terms were explained. Every prenuptial agreement we draft assumes someone may attack it later. If you are earlier in the process, start with whether you need a prenup at all.
Our family law attorneys represent clients in Macomb, Oakland, and Wayne Counties and throughout Southeast, Central, and Mid-Michigan, and we draft these agreements, defend them, and challenge them when the facts support it. To schedule a consultation, call Boroja, Bernier & Associates at (586) 991-7611.
About the Author
Joel Bernier, Esq. is a founding partner of Boroja, Bernier & Associates PLLC, where he leads the firm’s divorce and family law practice. He has practiced Michigan divorce and family law since 2010 (Bar No. P74226).
