Family · Prenuptial agreement
Prenuptial Agreement Requirements in Michigan
What makes a prenuptial agreement valid and enforceable in Michigan: the writing and signature, the voluntariness rule, the financial disclosure each side must give, and what gets a prenup thrown out. Cited to the statute.
What makes a prenuptial agreement valid in Michigan
The writing and signature, voluntariness, and financial disclosure a court looks for before it will enforce a prenup.
Michigan prenup validity rests on Court of Appeals case law, not a statute, and Allard v. Allard sets a genuine ceiling that even the broadest waiver cannot cross. Confirm the current holdings of Rinvelt v. Rinvelt and Allard v. Allard, and the equitable-power statutes MCL 552.23(1) and MCL 552.401, before relying on this.
| What makes a prenup valid | What it means |
|---|---|
| In writing and signed | MCL 566.132(1)(c) makes an agreement made upon consideration of marriage void unless it, or a memorandum of it, is in writing and signed by the party to be charged. Michigan uses the strong word void, which is firmer than the language some other states use. |
| Made in contemplation of marriage | 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. That is the statute that keeps a Michigan prenup alive rather than merging into the marriage. |
| Free of fraud, duress, mistake, or nondisclosure | The first Rinvelt factor asks whether the agreement was obtained through fraud, duress, or mistake, or misrepresentation or nondisclosure of material fact. Nondisclosure of a material fact is enough to defeat enforcement even without an outright lie. |
| Not unconscionable when executed | The second Rinvelt factor asks whether the agreement was unconscionable when executed, judged as of the signing. A deal so one-sided that one side gave up real rights for illusory promises can fail on this ground. |
| Fair disclosure to waive estate rights | For a waiver of the surviving spouse’s intestate share, homestead allowance, election, exempt property, or family allowance, MCL 700.2205 requires a signed writing made after fair disclosure. So a Michigan prenup can face a stricter disclosure standard at death than at divorce. |
| What makes a prenup unenforceable | What it means |
|---|---|
| Changed circumstances at enforcement | The third Rinvelt factor asks whether the facts and circumstances have changed since the agreement was executed so as to make enforcement unfair and unreasonable. Like Georgia, Michigan will consider what happened after the signing, not just the world at the time. |
| A prenup cannot waive the court’s power over separate property | Allard v. Allard holds that parties cannot, by antenuptial agreement, deprive a trial court of its equitable discretion under MCL 552.23(1) and MCL 552.401. Those statutes let a court reach separate property where the award is insufficient for support, or where the other spouse helped build the property. This ceiling holds no matter how broadly the waiver is drafted. |
| Mutual promises to marry | MCL 566.132(1)(c) expressly excepts mutual promises to marry from the writing requirement. The engagement itself does not need to be in writing. The property agreement does. |
| Contracts against public policy | The Allard court applied the general rule that contracts founded on prohibited acts or in violation of public policy are void. That is the doctrinal hook the court used to cap what a Michigan prenup can waive. |
What you can do right now
Concrete, neutral steps to sign a prenup that will hold up in Michigan. This is legal information, not legal advice.
- Put the agreement in writing and sign it
MCL 566.132(1)(c) makes the agreement void without a signed writing. Do not rely on any oral understanding, and keep the signed original, because Michigan treats the writing as a condition of validity rather than mere proof.
- Disclose finances, and disclose fully if estate rights are waived
Nondisclosure of a material fact can defeat the agreement under Rinvelt, and a waiver of surviving-spouse estate rights under MCL 700.2205 requires fair disclosure. Exchange complete asset and debt information and keep a record of it.
- Do not expect a waiver to override the court’s equity power
Under Allard v. Allard, no prenup can waive the court’s discretion to reach separate property under MCL 552.23(1) and MCL 552.401. Draft with that ceiling in mind rather than trying to word around it.
A prenuptial agreement decides property and support if a marriage ends, and a court will scrutinize how it was signed. A licensed family-law attorney can draft or review one; the state bar can refer you to one.
→ State Bar of Michigan, Lawyer Referral ServiceThis is general legal information, not legal advice. Enforceability turns on the exact statute, the case law, and how the agreement was signed, so confirm the current requirements against the statute and talk to a lawyer.
What couples in Michigan get wrong about prenups
Michigan has no Uniform Premarital Agreement Act, so its rule comes from a statute of frauds plus a line of Court of Appeals cases. The writing requirement is in MCL 566.132(1)(c), which says an agreement made upon consideration of marriage is void unless it, or a memorandum of it, is in writing and signed by the party to be charged, with an express carve-out for mutual promises to marry. MCL 557.28 supplies the other half, confirming that a property contract made in contemplation of marriage remains in full force after the marriage takes place. The validity test comes from Rinvelt v. Rinvelt, decided in 1991, which asks three questions: was the agreement obtained through fraud, duress, mistake, misrepresentation, or nondisclosure of material fact, was it unconscionable when executed, and have the facts and circumstances changed since it was executed so as to make enforcement unfair and unreasonable. On top of those factors Michigan has a hard ceiling that its neighbors lack. Under Allard v. Allard, decided on remand in 2017, parties cannot by antenuptial agreement deprive a trial court of its equitable discretion under MCL 552.23(1) and MCL 552.401, the statutes that let a court reach separate property. In Allard the waiver was about as broad as English allows, and it still did not reach that discretion. This is legal information, not legal advice.
Common questions
Is there a prenuptial agreement statute in Michigan?
No. Michigan has no prenup statute and no Uniform Premarital Agreement Act. The statute of frauds, MCL 566.132(1)(c), supplies the writing requirement, and the validity test comes from the Court of Appeals decision Rinvelt v. Rinvelt.
Can a Michigan prenup waive everything through a broad enough clause?
No. Under Allard v. Allard, no antenuptial agreement can strip a divorce court of its power to reach separate property under MCL 552.23(1) and MCL 552.401. An extremely broad waiver in Allard still did not reach that discretion.
Does a Michigan prenup require financial disclosure?
For divorce, there is no free-standing statutory duty, though nondisclosure of a material fact can defeat the agreement under Rinvelt. For waiving surviving-spouse estate rights, MCL 700.2205 requires fair disclosure, a stricter standard.
Can a Michigan court refuse to enforce a prenup that became unfair over time?
Yes. The third Rinvelt factor asks whether circumstances have changed since signing so as to make enforcement unfair and unreasonable, so Michigan, like Georgia, looks at the world at divorce, not only at the time of signing.
Not legal advicePlainStatute provides plain-language summaries of public law for general information only. This is not legal advice. Statutes change; always confirm current requirements with the official source linked above before acting.