What Should Be in a Prenup in Michigan: 2026 Complete Guide

A Michigan prenuptial agreement, formally called an antenuptial agreement under MCL 557.28, must be in writing and signed by both parties to be enforceable. Michigan courts apply the three-factor Rinvelt test to validate prenups, requiring voluntary execution, full financial disclosure, and terms that remain fair over time. Attorney costs for drafting a Michigan prenup range from $750 to $5,000 per spouse depending on complexity, with standard agreements averaging $1,500 total.

What Makes a Prenup Valid in Michigan

Michigan courts enforce prenuptial agreements that pass the Rinvelt v. Rinvelt three-factor validity test, established in 190 Mich App 372 (1991). This landmark case held that antenuptial agreements governing property division in divorce are enforceable when three conditions are met: the agreement was not obtained through fraud, duress, or misrepresentation; the terms were not unconscionable when executed; and changed circumstances have not made enforcement unfair. The party challenging the agreement bears the burden of proof.

The Three-Factor Rinvelt Test

Michigan courts examine prenuptial agreements using these three factors established in Rinvelt:

• Factor 1: Was the agreement obtained through fraud, duress, mistake, or non-disclosure of material facts
• Factor 2: Was the agreement unconscionable at the time of execution
• Factor 3: Have facts and circumstances changed since execution, making enforcement unfair and unreasonable

Statutory Requirements Under MCL 557.28

The Michigan Compiled Laws establish clear requirements for valid prenuptial agreements. MCL 557.28 states that "a contract relating to property made between persons in contemplation of marriage shall remain in full force after marriage takes place." Additionally, MCL 566.132(c) requires that any agreement made upon consideration of marriage must be in writing and signed by the party to be charged.

Essential Clauses to Include in a Michigan Prenup

Michigan prenuptial agreements should address property division, spousal support, debt allocation, and asset protection to be comprehensive and enforceable. A well-drafted prenup in Michigan includes 8-12 core provisions covering separate property identification, marital property classification, business interest protection, retirement account treatment, real estate ownership, debt responsibility, spousal support terms, and death provisions. Each clause must be specific and supported by full financial disclosure schedules.

Property Division Clauses

Michigan operates as an equitable distribution state, meaning courts divide property fairly but not necessarily equally (50/50). Prenuptial agreements can override this default by specifying exact division percentages or asset assignments. Property clauses should address:

• Separate property: Assets owned before marriage remain with original owner
• Marital property: Assets acquired during marriage classified according to agreement terms
• Appreciation: Whether appreciation on separate property remains separate or becomes marital
• Gifts and inheritances: Classification of property received from third parties
• The marital home: Who retains the residence or how sale proceeds are divided

Spousal Support Provisions

Michigan allows couples to set their own alimony terms in a prenup, including waiving support entirely. Under MCL 552.23, courts typically award alimony to balance the income needs of both parties so neither is unequally disadvantaged. Spousal support clauses in a Michigan prenup can specify:

• A complete waiver of alimony by one or both parties
• Fixed alimony amounts based on marriage duration (e.g., $2,000/month for marriages lasting 5+ years)
• Alimony caps or limits regardless of circumstances
• Non-modification language preventing future court changes
• Sunset provisions reducing support after certain milestones

Important limitation: Under MCL 552.23(1) and MCL 552.401, Michigan courts retain equitable power to award spousal support if a spouse would otherwise receive assets "insufficient for suitable support and maintenance." This means a court may override a prenup waiver if enforcement would leave one spouse destitute.

Debt Protection Clauses

Michigan law requires full disclosure of all debts as part of prenup execution, including student loans, mortgages, vehicle liens, and credit card balances. Debt protection clauses should:

• Assign pre-existing debts to the spouse who incurred them
• Specify responsibility for debts acquired during marriage
• Protect one spouse from the other's business-related debts
• Address how joint debts (mortgages, credit cards) will be handled
• Include indemnification provisions for debt-related claims

Business Interest Protection

For business owners in Michigan, a prenuptial agreement can designate business interests as separate property, preventing division in divorce. Approximately 65% of Michigan prenups include business protection clauses. Business provisions should address:

• Classification of the business as separate property
• Treatment of business appreciation during marriage
• Compensation for spouse's contributions to business growth
• Buyout provisions if business must be valued
• Restrictions on spouse's involvement in business decisions

Retirement Account Provisions

Michigan prenups can establish how 401(k)s, IRAs, pensions, and other retirement accounts are divided. Without a prenup, retirement benefits earned during marriage are subject to equitable distribution. Retirement clauses should specify:

• Pre-marital retirement account balances remain separate
• Contributions made during marriage: separate or marital
• QDRO (Qualified Domestic Relations Order) terms for 401(k) and pension division
• Social Security benefit considerations
• Military retirement benefits (if applicable)

What Cannot Be Included in a Michigan Prenup

Michigan law prohibits certain provisions in prenuptial agreements, and including unenforceable terms can jeopardize the entire agreement. Courts will strike clauses that violate public policy or statutory requirements. Understanding these limitations protects the overall validity of your prenup.

Child Custody Restrictions

Michigan family courts retain exclusive jurisdiction over child custody determinations. Any prenup clause attempting to predetermine custody arrangements is unenforceable because courts must evaluate the child's best interests at the time of separation, not years earlier when the prenup was signed.

Child Support Limitations

Michigan calculates child support using state guidelines under the Michigan Child Support Formula. Parents cannot waive, reduce, or fix child support amounts in a prenuptial agreement. Courts will ignore any prenup provisions attempting to modify child support obligations.

Provisions Encouraging Divorce

Michigan courts may invalidate prenup clauses that appear designed to incentivize divorce, such as:

• Bonus payments triggered by filing for divorce
• Provisions that penalize a spouse for attempting reconciliation
• Terms that reward infidelity or bad behavior

Unconscionable Terms

Under the Rinvelt test, agreements that are grossly unfair or one-sided when executed may be unenforceable. Examples include:

• Waiving all property rights leaving one spouse with nothing
• Extreme alimony waivers when one spouse has no earning capacity
• Terms that would leave a spouse unable to support themselves

Financial Disclosure Requirements

Michigan prenuptial agreements require full and fair disclosure of all financial information from both parties. This duty of disclosure is higher than in typical contract negotiations. Failure to disclose assets, debts, or income can render the entire agreement void. Courts have invalidated prenups where one party hid bank accounts, undervalued businesses, or failed to reveal significant debts.

Required Disclosures

Both parties must provide complete disclosure of:

Disclosure Schedules

Michigan attorneys typically attach financial disclosure schedules as exhibits to the prenup. Schedule A lists one spouse's assets and debts; Schedule B lists the other's. These schedules become part of the enforceable agreement and establish the baseline for separate property claims.

Timing and Execution Requirements

Michigan does not impose a specific statutory waiting period between presenting a prenup and signing, but courts evaluate timing when assessing voluntariness. Presenting a prenup the night before the wedding increases the risk of a duress challenge. Best practice recommends completing and signing the agreement at least 30 days before the wedding date.

Execution Best Practices

To maximize enforceability, Michigan prenups should be executed following these guidelines:

• Both parties should have separate, independent legal counsel
• Sign the agreement at least 30 days before the wedding
• Include notarized signatures (strongly recommended)
• Attach complete financial disclosure schedules
• Keep original signed copies for both parties
• Avoid signing under time pressure or emotional duress

Independent Legal Counsel

While Michigan does not legally require each party to have an attorney, prenups executed without independent counsel face higher scrutiny. Courts are more likely to enforce agreements where both parties had legal representation and opportunity to negotiate terms.

Sunset Clauses in Michigan Prenups

Michigan recognizes sunset clauses that terminate or modify prenup provisions after a specified period. For example, a sunset clause might state that after 15 years of marriage, the waiver of spousal support expires and standard Michigan alimony guidelines apply. Approximately 25% of Michigan prenups include some form of sunset provision.

Types of Sunset Clauses

• Time-based: Prenup expires entirely after 10, 15, or 20 years of marriage
• Partial sunset: Certain provisions (e.g., alimony waiver) expire while property division terms remain
• Milestone-based: Provisions change upon birth of children or reaching certain assets
• Phase-out: Gradual increase in property rights over marriage duration

Pending Legislative Changes: Senate Bill 160

Michigan Senate Bill 160, which would adopt the Uniform Premarital and Marital Agreements Act (UPMAA), passed the Michigan Senate on June 18, 2025, and awaits action in the Michigan House of Representatives as of March 2026. If enacted, this legislation would create Michigan's first comprehensive prenuptial agreement statute, replacing the current common law framework.

Key Provisions in SB 160

The proposed UPMAA legislation would:

• Require both parties to sign in record
• Define duress to include threats related to calling off the wedding
• Consider timing of presentment relative to wedding announcements
• Make premarital agreements effective upon marriage
• Apply only to agreements signed after the Act's effective date
• Take effect six months after enactment

Cost of a Michigan Prenup in 2026

A Michigan prenup attorney charges approximately $750 per spouse as a flat fee for a standard prenuptial agreement in 2026. Complex prenups involving business interests, trusts, or high-value estates cost $1,500 to $5,000 per spouse. The total cost for a married couple typically ranges from $1,500 to $10,000 when both spouses retain separate counsel.

Cost Breakdown

Additional Costs

Beyond attorney fees, expect these additional expenses:

• Notarization: $10-$25
• Financial advisor consultation: $150-$500/hour
• Business valuation (if needed): $5,000-$15,000
• Real estate appraisal (if needed): $300-$600

Postnuptial Agreements as an Alternative

Michigan also recognizes postnuptial agreements for couples who are already married. These agreements follow similar enforceability standards as prenups but face slightly higher scrutiny because the parties are already in a confidential marital relationship. Postnuptial agreements can address the same topics as prenups: property division, spousal support, debt allocation, and asset protection.

FAQs About Michigan Prenups

Can a prenup waive alimony in Michigan?

Yes, Michigan prenups can waive alimony entirely, though courts retain discretion under MCL 552.23(1) to award support if enforcement would leave a spouse without sufficient means for suitable support. Approximately 40% of Michigan prenups include full alimony waivers.

Is a prenup valid without a lawyer in Michigan?

Yes, Michigan does not legally require attorney involvement for a valid prenup. However, agreements executed without independent counsel face higher judicial scrutiny, and courts are significantly more likely to enforce prenups where both parties had separate attorneys review the terms.

How far in advance should a Michigan prenup be signed?

Michigan recommends signing prenups at least 30 days before the wedding to avoid duress claims. While no statutory waiting period exists, presenting a prenup within 24-48 hours of the ceremony substantially increases the risk of invalidation. Courts examine whether both parties had adequate time to review and negotiate terms.

Can a prenup protect my business in Michigan?

Yes, Michigan prenups can designate business interests as separate property, protecting them from division in divorce. Business protection clauses should address ownership classification, appreciation during marriage, and buyout provisions. Approximately 65% of prenups involving business owners include these protections.

What happens if my spouse doesn't disclose all assets?

Incomplete financial disclosure can void a Michigan prenup entirely. Under the Rinvelt test, fraud or misrepresentation of material facts is grounds for invalidation. Courts have struck down prenups where one party hid bank accounts, undervalued businesses, or failed to disclose significant debts.

Can we include a sunset clause?

Yes, Michigan recognizes sunset clauses that terminate or modify prenup provisions after specified periods. Common sunset triggers include 10-15 years of marriage, birth of children, or reaching certain asset thresholds. Approximately 25% of Michigan prenups include sunset provisions.

Does Michigan require prenups to be notarized?

Michigan does not legally require notarization, but strongly recommends it for enforceability. Notarized prenups provide stronger evidence of voluntary, informed execution and are significantly less likely to face successful challenges.

Can a prenup address inheritance rights?

Yes, Michigan prenups can waive or modify inheritance rights, including the statutory share a surviving spouse would otherwise receive. These provisions must be clearly stated and both parties must understand the rights being waived.

What if circumstances change dramatically after signing?

Under the third Rinvelt factor, Michigan courts may refuse to enforce a prenup if facts and circumstances have changed so significantly that enforcement would be unfair and unreasonable. However, courts have held that foreseeable changes like long marriages, asset growth, or having children do not typically justify invalidation.

How is a prenup enforced during divorce in Michigan?

During divorce proceedings, a party seeking to enforce a prenup presents it to the court as governing the terms of property division and spousal support. The opposing party may challenge validity under the Rinvelt three-factor test. If upheld, the prenup terms control over Michigan's default equitable distribution rules.