Michigan: Prenuptial Agreement Requirements

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 2026-07-27).