Prenuptial Agreement Requirements in Michigan

At a glance

Requirements one by one

Michigan uses narrow statutes plus case law

Michigan has not enacted the UPAA or UPMAA. MCL 557.28 preserves a property contract made in contemplation of marriage after the wedding, and the statute of frauds in MCL 566.132 supplies the writing-and-signature rule. Benker, Reed, and Allard supply the important disclosure, fairness, and public-policy limits.

Pending SB 160 would create a comprehensive uniform premarital and marital agreements act. It passed the Senate in 2025 but remains in the House Judiciary Committee, so it is not current law.

The statute requires a signed writing, not necessarily both signatures

MCL 566.132(1) makes a marriage-consideration agreement void unless it or a memorandum is written and signed by the party to be charged. That is not the same text as a uniform act requiring both prospective spouses to sign for every purpose. In practice, signatures from both parties avoid one-sided enforcement problems, but the dimension reports Michigan's actual statute.

Benker explains that marriage alone is sufficient consideration and need not be recited. Under MCL 557.28, a contemplated-marriage property contract remains in force after the marriage occurs.

No notary, witnesses, or recording are universal validity conditions

Neither MCL 557.28 nor the applicable part of MCL 566.132 requires a notarial acknowledgment, witness, attestation, oath, or recording. Reed's fairness test does not add one. A notary block may still help authenticate signatures, and a separate transaction involving real property may have its own recording rules, but neither is a universal prenup formality.

Fair disclosure and informed understanding are central

Benker describes the parties' relationship as one of extreme mutual confidence and imposes a special duty of disclosure. The agreement must be voluntary, and each party must understand the rights being waived. Reed likewise includes material nondisclosure and misrepresentation in its first invalidity route.

For a surviving-spouse waiver, current MCL 700.2205 expressly requires fair disclosure. Michigan's current prenup statutes contain no UPAA-style provision allowing a separate written waiver of further disclosure or substituting reasonably available adequate knowledge for actual disclosure.

Benker generally places the burden on the challenger, but its particular facts created a rebuttable presumption of nondisclosure. Those facts included a total waiver, a large disparity in estates, hidden wealth, no agreement recital about disclosure, no independent counsel, and weak evidence from the drafter.

Counsel is not mandatory, and there is no statutory clock

Reed expressly says that, if the fairness requirements are satisfied, independent representation is not required before entering the contract. The absence of counsel can still matter to whether disclosure occurred and whether the signer understood the rights waived, as Benker illustrates.

No current Michigan statute or controlling test supplies a fixed final-draft review period or a minimum number of days between signing and the wedding. Timing remains relevant to the fact-specific questions of duress and voluntary, informed assent.

Reed applies a three-part fairness test

Reed, restating Rinvelt, permits a challenge for fraud, duress, mistake, material misrepresentation or nondisclosure; unconscionability when the agreement was executed; or sufficiently changed facts and circumstances making enforcement unfair and unreasonable. The challenger bears the burden of proof and persuasion.

For the changed-circumstances branch, foreseeability is the gate. Reed held that a long marriage and disparate asset growth were foreseeable and therefore did not justify setting the agreement aside on its facts.

Support terms cannot eliminate the court's statutory discretion

Allard treats an antenuptial agreement about spousal support as a contract “relating to property” under MCL 557.28. But that does not let the parties erase the court's authority. MCL 552.23(1) authorizes support or an additional property award when the estate and effects awarded are insufficient for suitable support and maintenance, and Allard holds that an agreement restraining that equitable authority is void against statute and public policy.

Allard applies the same principle to MCL 552.401, which permits an equitable award from separately owned property when the other spouse contributed to its acquisition, improvement, or accumulation.

Child support and custody remain for the court

MCL 552.605 generally requires the Michigan Child Support Formula. Even an agreed deviation requires the court to make the findings listed in the statute. Allard states that parents cannot bargain away a child's welfare, support right, or the court's support authority.

Custody likewise remains a judicial decision. MCL 722.23 requires the court to consider, evaluate, and determine the statutory best-interest factors, including domestic violence and any other relevant factor.

Current statutes provide no special prenup amendment route

MCL 557.28 and 566.132 do not state a prenup-specific post-marriage amendment or revocation procedure. The original property agreement therefore remains in force unless lawfully changed or rescinded; a private template's notarized- amendment clause should not be described as a Michigan statutory requirement.

One narrower rule is express: MCL 700.2205 permits a written, signed waiver of specified surviving-spouse rights either before or after marriage, after fair disclosure. That estate-rights route is not a general UPAA amendment statute.

What trips people up

• Michigan is not currently a uniform-act state. Pending SB 160 does not change the law unless it completes the legislative process and takes effect.
• The signature text is unusual. MCL 566.132 says “signed ... by the party to be charged,” not “signed by both parties.”
• Allard is not a blanket ban on support terms. It recognizes that support agreements relate to property, but preserves the court's statutory equitable authority under MCL 552.23 and 552.401.
• No fixed waiting period does not make last-minute signing safe. Duress, voluntariness, understanding, and material disclosure remain factual issues.

Common questions

Can unequal asset growth invalidate the agreement years later?

Not by itself. Reed held that acquiring separate assets, unequal growth, and a long marriage were foreseeable under the agreement before it. The changed- circumstances branch requires an event not reasonably foreseen when the parties made the agreement.

Must both people have lawyers?

No categorical rule requires it. Reed rejected lack of counsel as an automatic basis to void the agreement when the fairness rules were otherwise satisfied. Benker shows why counsel remains important evidence of disclosure and informed understanding in a difficult case.

Can a prenup waive inheritance and elective rights?

MCL 700.2205 permits a prospective or current spouse, after fair disclosure, to sign a written waiver of intestacy, homestead allowance, election, exempt property, and family allowance rights. The statute does not require that waiver to be a separate document.

Statutes and sources

• MCL 557.28 and MCL 566.132(1)(c) — continuing force after marriage and the signed-writing statute of frauds. Official § 557.28 PDF and official § 566.132 (accessed 2026-07-27).
• In re Benker Estate, 416 Mich. 681 (1982) — voluntariness, informed understanding, fair disclosure, burden, and the fact-specific rebuttable presumption. Michigan Supreme Court opinion (accessed 2026-07-27).
• Reed v. Reed, 265 Mich. App. 131 (2005) — three-part fairness test, challenger burden, foreseeability, and no categorical counsel requirement. Michigan Court of Appeals opinion (accessed 2026-07-27).
• MCL 552.23 and MCL 552.401 — equitable support and separate-property authority. Official § 552.23 and official § 552.401 (accessed 2026-07-27).
• Allard v. Allard, 318 Mich. App. 583 (2017) — support as a property- related term and nonwaivable judicial authority under §§ 552.23 and 552.401. Official published opinion (accessed 2026-07-27).
• MCL 552.605 and MCL 722.23 — child-support formula and custody best- interest factors. Official § 552.605 and official § 722.23 (accessed 2026-07-27).
• MCL 700.2205 — written surviving-spouse waiver before or after marriage following fair disclosure. Official statute (accessed 2026-07-27).
• SB 160 (2025-2026) — pending proposal for a Michigan uniform act. Official bill page (checked 2026-08-27).