Are prenups enforceable in Michigan?
Yes. Michigan enforces prenuptial agreements, called antenuptial agreements, but it does so through common law and statute rather than the Uniform Premarital Agreement Act. Courts apply the Rinvelt standard of fairness, voluntariness, and disclosure. Neptune is the lawyer-led online prenup service: both partners get their own Michigan-licensed lawyer for one flat fee.
$5,000 flat fee per couple. Two independent attorneys included.
How Michigan differs
Most states have adopted a uniform statute that spells out prenup rules. Michigan has not. Instead, enforceability comes from a line of court decisions, anchored by Rinvelt v. Rinvelt, together with the statute recognizing marriage property contracts (MCL 557.28). That makes case law unusually important here.
Michigan’s distinguishing feature
A court keeps some discretion the agreement cannot waive
In Allard v. Allard (2017), the Michigan Court of Appeals held that parties cannot, by antenuptial agreement, completely strip a trial court of its equitable discretion under MCL 552.23(1) and MCL 552.401. A Michigan court can retain some authority to reach a spouse’s separate property for suitable support, or where the other spouse contributed to its growth, even alongside a valid agreement. Good drafting works with this limit rather than against it, which is one reason experienced Michigan counsel matters here.
What a Michigan prenup should include
In writing and signed by both parties
Michigan recognizes antenuptial contracts by statute (MCL 557.28), and courts look for a written agreement signed by both parties.
Notarization strongly advisable
Michigan does not require notarization by statute, but having signatures notarized, and often witnessed, helps authenticate the agreement if it is later challenged.
Independent counsel for each party
Michigan does not strictly require separate attorneys, but independent counsel for each partner supports a finding that the agreement was voluntary and informed.
Signed well before the wedding
Agreements signed under time pressure just before the ceremony are more vulnerable to a duress challenge. More lead time supports enforceability.
The Rinvelt standard
When a Michigan court is asked whether to enforce an antenuptial agreement, it generally looks at three things. Meeting all three is the surest path to an agreement that holds up.
Fair, equitable, and reasonable
Under Rinvelt v. Rinvelt (1991), a Michigan antenuptial agreement must be fair, equitable, and reasonable in view of the surrounding facts and circumstances.
Entered into voluntarily
Both parties must enter the agreement voluntarily, with each understanding their rights and the effect of the agreement. Signing under duress can render it unenforceable.
Full and fair disclosure
Each party should have full knowledge of the other’s property and financial circumstances before signing, or knowingly waive that disclosure.
Michigan courts can also weigh whether circumstances changed so dramatically after signing that enforcement would be unfair. Your attorney can explain how these standards apply to your situation.
What a prenup costs in Michigan
Both partners should have independent representation. Here is how the traditional route compares with Neptune, per couple.
Traditional firms
$1,500–$10,000+
per couple
Two separate attorneys, each billed separately
Often hourly, so the total is uncertain
Higher for business interests or trusts
Detroit and Ann Arbor rates at the higher end
Neptune
$5,000
flat fee, both attorneys included
No hourly billing. No payment to start.
Rush pricing applies when the wedding is within 45 days.
How Neptune works in Michigan
Michigan’s fairness standard and its case law inform every step. Your attorneys focus on financial disclosure and voluntary consent to support enforceability.
Guided intake and attorney connection
Answer questions about your finances, goals, and concerns. Neptune connects each partner with an independent Michigan-licensed attorney who understands the Rinvelt standard and how Michigan courts review antenuptial agreements.
Drafting with disclosure built in
Your drafting attorney prepares the agreement while guiding you through financial disclosure. The reviewing attorney independently represents the other partner, supporting the voluntariness Michigan courts examine.
Review, negotiation, and signing
Both attorneys negotiate terms and work to confirm the agreement fits Michigan’s fairness standard. Building in lead time before the wedding helps reduce the risk of a duress challenge.
Turnaround is typically around 3 to 4 weeks when both partners use Neptune attorneys.
Last update
The information on this page was last updated in July 2026. Neptune is not a law firm and does not provide legal advice. The content on our website related to legal matters ("Legal Information") is provided for your private use and general informational purposes only. We do not review any information you provide us for legal accuracy or sufficiency, draw legal conclusions, provide opinions about your selection of forms, or apply the law to the facts of your situation. If you need legal advice for a specific problem, you should consult with a licensed attorney. Neither Neptune nor any information provided by Neptune is a substitute for legal advice from a qualified attorney licensed to practice in an appropriate jurisdiction.
Michigan prenup questions
Does Michigan follow the Uniform Premarital Agreement Act?
No. Michigan is one of the states that has not adopted the Uniform Premarital Agreement Act. Instead, enforceability of a Michigan prenuptial agreement, called an antenuptial agreement, is governed by common law developed through court decisions and by statute (MCL 557.28), which recognizes that a property contract made in contemplation of marriage remains in force after the marriage. A bill to adopt a uniform act has been considered in the Michigan Legislature, but as of this update Michigan still relies on its case law framework. Your attorney can explain the current state of the law.
What is the Rinvelt test?
Rinvelt v. Rinvelt (1991) is the Michigan Court of Appeals decision confirming that antenuptial agreements governing the division of property in the event of divorce are enforceable in Michigan, within limits. Courts applying Rinvelt generally look at three things: whether the agreement is fair, equitable, and reasonable given the circumstances; whether it was entered into voluntarily with each party understanding their rights; and whether there was full and fair disclosure of each party’s finances. An agreement that meets these standards is far more likely to be enforced.
Can a Michigan prenup waive everything a court might otherwise do?
Not entirely. In Allard v. Allard (2017), the Michigan Court of Appeals held that parties cannot, through an antenuptial agreement, completely strip a trial court of its equitable discretion under MCL 552.23(1) and MCL 552.401. This means a Michigan court can retain some authority to divide property for a spouse’s suitable support, or where one spouse contributed to the acquisition or growth of the other’s separate property, even alongside a valid agreement. Your attorney can explain how to draft with this limit in mind.
How does Michigan divide property without a prenup?
Michigan divides marital property through equitable distribution, meaning a court divides assets in a way it considers fair, which is not always an equal split. Courts weigh factors such as the length of the marriage, each spouse’s contributions, earning ability, age, health, needs, and even fault, following the framework in Sparks v. Sparks (1992). Separate property is generally protected but can, in some circumstances, be reached under MCL 552.401. A prenup lets a couple set their own terms rather than leaving these questions to a judge.
How much does a prenup cost in Michigan?
Traditional attorney-drafted prenups in Michigan commonly run from around $1,500 to $10,000 or more per couple when both partners retain separate counsel, with complex or high-net-worth agreements at the higher end. Neptune offers a $5,000 flat fee that includes two independent attorneys, one for each partner, with no hourly billing and no payment required to start. By comparison, a contested divorce without an agreement can cost far more.
How long does the prenup process take?
When both partners use Neptune attorneys, turnaround is typically around 3 to 4 weeks. The timeline includes drafting, independent review, financial disclosure, and negotiation. Because Michigan courts scrutinize agreements signed under time pressure, building in lead time before the wedding is worthwhile. Rush pricing applies when the wedding is within 45 days.
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Reviewed by
Michael Cotugno, Esq.
Managing Partner, Neptune Legal · 30+ years practicing family law