Everything engaged couples need to know about making a prenuptial agreement valid and enforceable in Michigan — in plain English, reviewed by attorney James Sexton, Esq.
Yes — prenuptial agreements are legal and enforceable in Michigan, including in divorce, not just at death.
Michigan's statutory hook is short: 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 enforcement rules come from case law. Rinvelt v. Rinvelt, 190 Mich. App. 372 (1991), confirmed that prenups are enforceable in divorce, not only at death. Allard v. Allard, 499 Mich. 932 (2016), added the modern caveat: even a valid prenup cannot waive a court's independent equitable powers under MCL 552.23(1) and MCL 552.401 to reach separate assets when a spouse would otherwise be left without suitable support.
A Michigan prenup is enforceable when it was signed voluntarily with honest disclosure, wasn't unconscionable at signing, and enforcing it hasn't become unfair through changed circumstances.
The agreement should be a written contract signed by both parties before the marriage, consistent with MCL 557.28 and Michigan's statute of frauds.
The agreement fails if it was obtained through fraud, duress, mistake, or misrepresentation or nondisclosure of a material fact. Michigan practice is to attach each party's full asset and debt schedules as exhibits.
The terms can favor one spouse, but they can't be so one-sided at signing that no sensible person would agree — that's the unconscionability line Michigan courts police.
Michigan courts also ask whether the facts and circumstances have changed since signing so dramatically that enforcement would be unfair and unreasonable. And under Allard, courts always keep their statutory power to prevent a spouse from being left without suitable support.
| Governing statute | MCL 557.28 + Rinvelt v. Rinvelt (1991) and Allard v. Allard (2016) (no UPAA) |
|---|---|
| Property division | Equitable distribution |
| Notarization | Recommended (not required by statute) |
| Waiting period | None required — but sign well before the wedding |
| Spousal support | Can be waived, but courts keep equitable power to award support under Allard |
See how Michigan's signing formalities compare in our prenup notarization requirements by state guide.
Michigan courts set aside prenups obtained by fraud, duress, or nondisclosure, that were unconscionable when signed, or whose enforcement has become unfair because circumstances changed dramatically during the marriage.
Michigan gives a challenger three routes, and its changed-circumstances doctrine is broader than most states'. Still, the challenge courts see most is nondisclosure — which is why attaching complete financial exhibits is standard practice. Since Allard v. Allard, there's also a structural limit: no matter how airtight the drafting, a prenup can't eliminate the court's statutory discretion under MCL 552.23(1) and 552.401 to reach separate assets when one spouse would otherwise lack suitable support. Full exhibits, an early signing, and terms that stay livable are what make a Michigan prenup hold.
Trusted Prenup creates a state-specific Michigan prenuptial agreement online — built to meet the requirements above and designed by James Sexton, Esq. A traditional attorney typically costs $2,500–$10,000; this is a flat $599.
A guided questionnaire captures your assets, debts, and wishes — most couples finish in under 90 minutes.
We assemble a complete prenup built to meet your state's exact legal requirements.
Review with your partner, then sign online with notarization handled for you.
A Michigan attorney-drafted prenup typically costs $1,500–$6,000 or more. Trusted Prenup creates a state-specific Michigan prenup online for a flat $599, with optional notarization and attorney-review add-ons.
No — MCL 557.28 does not require notarization for a prenuptial agreement to be valid. Notarizing is still strongly recommended as proof of authenticity, and it's available as an add-on.
Yes, on three grounds: it was obtained by fraud, duress, mistake, or nondisclosure of a material fact; it was unconscionable when executed; or the facts have changed since signing so that enforcement would be unfair and unreasonable.
Allard (2016) held that couples cannot contract away a court's independent equitable powers under MCL 552.23(1) and MCL 552.401. Even with a valid prenup, a judge can reach separate assets if a spouse would otherwise be left without suitable support and maintenance.
Yes, a Michigan prenup can waive or limit spousal support — but the waiver isn't absolute. Under Allard, courts retain statutory power to award support from separate assets if enforcing the waiver would leave a spouse without suitable support.
No. Michigan is an equitable-distribution state — judges divide marital property fairly, not automatically 50/50. A prenup is how couples decide the split themselves rather than leaving it to a judge's discretion.
Yes — Michigan enforces properly executed prenuptial agreements regardless of how they were drafted. What matters is execution: a written agreement, voluntary signatures, full financial disclosure, and Michigan's signing formalities. The full picture is in are online prenups legally binding.
Trusted Prenup is not a law firm and does not provide legal advice. This guide is general information about Michigan law and not a substitute for advice from a licensed attorney about your situation.