Are prenuptial agreements enforceable in Michigan?

Michigan follows a common-law framework anchored by Rinvelt and statutory recognition of spousal contracts.

1. Governing Statute / Common Law

MCL 557.28 authorizes contracts between spouses concerning property. Rinvelt v. Rinvelt, 190 Mich. App. 372 (1991), controls prenup enforcement. Michigan has not adopted the UPAA.

2. Formality Requirements

The agreement must be in writing and signed by both parties. While not statutorily required, witnesses and notarization are best practice. Marriage is the consideration; the agreement becomes effective at marriage.

3. Voluntariness

Rinvelt prong one asks whether the agreement was procured by fraud, duress, mistake, or misrepresentation. Time pressure, lack of counsel, and emotional state are considered. Eve-of-wedding signings draw scrutiny but are not automatically void.

4. Disclosure

Rinvelt prong three requires full disclosure of assets, debts, and income (or that the challenger had independent knowledge). Failure to disclose material assets frequently invalidates Michigan prenups.

5. Unconscionability and Changed Circumstances

Rinvelt prong two examines unconscionability at execution. Prong four uniquely asks whether circumstances have changed since execution so that enforcement would be unfair and unreasonable — a forward-looking equitable check.

6. What Cannot Be Waived

Child support and custody cannot be predetermined. Spousal support waivers are more heavily scrutinized than property waivers; Reed v. Reed, 265 Mich. App. 131 (2005), confirmed that property provisions of a valid prenup are enforced, but spousal-support waivers fall under the court's general equitable discretion at divorce.

7. Key Michigan Case Law

Rinvelt v. Rinvelt (1991); Reed v. Reed (2005); Allard v. Allard, 318 Mich. App. 583 (2017), reaffirming the court's equity power over spousal-support provisions and modifying Rinvelt's reach.

This is legal information, not legal advice.