Clients ask about “a prenup.” Wisconsin law does not use that word. What this state has is the marital property agreement, governed by Wis. Stat. § 766.58, and getting the terminology right is not pedantry — it is the first clue that Wisconsin handles these documents differently from most states, and that a form downloaded from the internet is unlikely to do what the couple signing it believes it does.
The central thing to understand is that two different chapters of the statutes are in play, and they answer two different questions. Chapter 766, the Uniform Marital Property Act, classifies property during the marriage — who owns what, who may manage it, what happens at death. Chapter 767 governs what a court does with property at divorce. An agreement drafted under § 766.58 does not automatically control a divorce court. It enters the divorce through a separate door, § 767.61 (3) (L), and it is tested there under a standard the Wisconsin Supreme Court built in 1986. A great many agreements that are perfectly valid under ch. 766 do not survive that test.
What the statute requires to make one at all
The formal requirements in § 766.58 (1) are spare. A marital property agreement is a document signed by both spouses. Only the spouses may be parties to it — a parent underwriting the marriage, a family business, a trustee, none of them can be a party. And it is enforceable without consideration, which spares it the usual contract problem of what each side gave up.
Two further mechanics matter. Under § 766.58 (5), people intending to marry each other may enter into a marital property agreement as if they were already married, but it becomes effective only upon the marriage. That subsection is the entire statutory basis for what everyone calls a prenuptial agreement. And under § 766.58 (4), such an agreement may be amended or revoked only by a later marital property agreement — not by a letter, not by a handshake, not by conduct, and not by a will.
Section 766.58 (11) permits married persons or persons intending to marry to record the agreement with the county register of deeds under § 59.43 (1c) (a). That is optional, and it is usually worth doing where real estate is involved.
What an agreement can control
Section 766.58 (3) is a broad grant. Subject to the exceptions discussed in the next section, spouses may agree with respect to:
- Rights in and obligations with respect to any of either or both spouses’ property, whenever and wherever acquired or located — § 766.58 (3) (a).
- Management and control of that property — par. (b).
- Disposition of that property upon dissolution or death, or upon the occurrence or nonoccurrence of any other event — par. (c).
- Modification or elimination of spousal support, except as provided in sub. (9) — par. (d).
- Making a will, trust, or other arrangement to carry out the agreement — par. (e).
- Passing property at death, including after-acquired property, to a designated person, trust, or entity without probate, by nontestamentary disposition — par. (f).
- Choice of law governing construction of the agreement — par. (g).
- Any other matter affecting either or both spouses’ property not in violation of public policy or a statute imposing a criminal penalty — par. (h).
That last catchall is wide, and § 766.17 (1) confirms the general principle: a marital property agreement may vary the effect of ch. 766. But the exceptions are where the practical work is.
Two details on the nonprobate-transfer power in par. (f) are worth flagging because they surprise people. Such a provision is revoked upon dissolution of the marriage, as provided in § 767.375 (1). And ch. 854 applies to transfers at death under a marital property agreement — § 766.58 (3m). The supreme court has held that neither § 766.58 (3) nor § 705.20 permits parties to ignore ch. 854 or to agree to prohibit court involvement in implementing a marital property agreement; that a provision permits transfer without probate does not mean the parties may contract away the creation of a reliable and public record of the transfer. Maciolek v. City of Milwaukee Employes’ Retirement System Annuity & Pension Board, 2006 WI 10.
What an agreement cannot do
The limits come from four places, and none of them can be drafted around.
It may not adversely affect a child’s right to support. Section 766.58 (2) says so flatly, and the exception is carried into § 766.17 (1) as well. A provision purporting to fix, cap, or waive child support has no effect on the child’s entitlement.
It may not vary the duty of good faith between the spouses. Under § 766.15 (1), each spouse must act in good faith with respect to the other in matters involving marital property or the other spouse’s property, and the subsection states expressly that “[t]his obligation may not be varied by a marital property agreement.” Intentional misrepresentation breaches that duty, and the court of appeals has held that the exclusive pre-divorce remedy for the breach is § 766.70 (1). Gardner v. Gardner, 175 Wis. 2d 420 (Ct. App. 1993).
It generally cannot be used against creditors who did not know about it. This is the exception most often overlooked, and it defeats the common assumption that an agreement can insulate one spouse’s assets from the other spouse’s debts. Under § 766.55 (4m), no provision of a marital property agreement adversely affects a creditor’s interest unless the creditor had actual knowledge of that provision when the obligation was incurred — or, for an open-end plan, when the plan was entered into. A creditor who learns of the provision afterward is not bound as to that obligation. Section 859.18 (6) carries the same principle past a spouse’s death: a provision disposing of property at death does not affect what is available for satisfaction of obligations unless that property was already unavailable under the agreement while both spouses were alive and the agreement binds the creditor under § 766.55 (4m) or § 766.56 (2) (c). Section 766.17 (2) points to that rule expressly.
It cannot defeat a bona fide purchaser. Marital property purchased by a bona fide purchaser from the spouse who had the right to manage and control it under § 766.51 is acquired free of the other spouse’s claim, and § 766.57 (3) provides that the effect of that subsection “may not be varied by a marital property agreement.” Under § 766.57 (2), notice of the existence of a marital property agreement does not by itself affect a purchaser’s bona fide status.
Two further boundaries deserve a line each. Section 766.58 (14) notes that limitations on the effect of these agreements for state income tax purposes are set out in ch. 71 — classification for property purposes and classification for tax purposes are not the same exercise. And under § 766.58 (9) (a), modification or elimination of spousal support during the marriage may not result in a spouse having less than necessary and adequate support, taking all sources of support into account. Paragraph (b) goes further: if an agreement modifies or eliminates spousal support so as to make one spouse eligible for public assistance at dissolution or at the death of the other, the court may require the other spouse or that spouse’s estate to provide support sufficient to avoid that eligibility, notwithstanding the agreement. A waiver that would put a spouse on public assistance is a waiver the court can override.
Unenforceability under chapter 766
Section 766.58 (6) sets out three grounds, and the burden is on the spouse resisting the agreement. An agreement executed before or during marriage is not enforceable if that spouse proves any of the following: it was unconscionable when made; that spouse did not execute it voluntarily; or, before execution, that spouse both (1) did not receive fair and reasonable disclosure, under the circumstances, of the other spouse’s property or financial obligations, and (2) did not have notice of them.
Note the structure of the third ground. It is conjunctive. A spouse who received no formal disclosure but who did have notice of the other’s holdings has not made out that ground.
Two more rules from § 766.58 (8). Whether an agreement is unconscionable is a question for the court to decide as a matter of law — not a jury question, and not a matter of the parties’ characterization. And the fact that both parties were represented by one lawyer, or that one party had a lawyer and the other did not, “does not by itself make a marital property agreement unconscionable or otherwise affect its enforceability.” That is a genuine statutory safe harbor, and it is narrower than it looks: by itself is doing real work, and the absence of independent counsel remains a factor in the divorce-court analysis below.
The part most agreements get wrong: what happens at divorce
Here is the pivot. A divorce court dividing property acts under § 767.61, not ch. 766. Section 767.61 (2) (a) sets aside property acquired by gift from a person other than the other party, by reason of the death of another, or with funds acquired in either of those ways — though under par. (b) even that property may be divided where refusing to divide it would create a hardship on the other party or on the children of the marriage. Section 767.61 (3) then presumes that all remaining property is divided equally, subject to thirteen listed factors.
The agreement is one of those factors. Section 767.61 (3) (L) provides:
Any written agreement made by the parties before or during the marriage concerning any arrangement for property distribution; such agreements shall be binding upon the court except that no such agreement shall be binding where the terms of the agreement are inequitable as to either party. The court shall presume any such agreement to be equitable as to both parties.
Two things follow immediately. The presumption runs in favor of the agreement, and the burden of production and persuasion rests on the spouse attacking it. Button v. Button, 131 Wis. 2d 84 (1986); see also Greenwald v. Greenwald, 154 Wis. 2d 767 (Ct. App. 1990). But the court retains an independent obligation to review the agreement, because, as Button put it, marriage is not simply a contract between two parties but a legal status in which the state has a special interest. The parties are free to contract, but they contract in the shadow of the court’s duty to examine the bargain at divorce.
The Button test
In Button, the supreme court held that an agreement is inequitable — and therefore not binding — if it fails to satisfy any one of three requirements:
- Each spouse has made fair and reasonable disclosure to the other of his or her financial status;
- Each spouse entered into the agreement voluntarily and freely; and
- The substantive provisions of the agreement dividing property upon divorce are fair to each spouse.
The first two are questions of procedural fairness and are assessed as of the date of execution. The third is substantive fairness, assessed as of execution and — if circumstances have significantly changed since — also at the divorce. Button, 131 Wis. 2d 84.
Disclosure. An agreement is inequitable if either spouse failed to make fair and reasonable disclosure of assets, liabilities, and debts. Independent knowledge of the other’s financial status can substitute for disclosure — but Schumacher v. Schumacher, 131 Wis. 2d 332 (1986), decided the same day, drew the line hard: independent knowledge “is not a general or imputed knowledge of the other’s assets and their value.” In Schumacher the wife might have assumed her husband had a pension, since she was similarly employed. That surmise was not the equivalent of knowing he had both a pension and an annuity worth more than $60,000, and the agreement fell. The court added the other half of the rule in the same breath: the disclosure requirement “is not so technical that de minimis failures to disclose will invalidate an agreement.”
The reason the standard is this demanding is stated in Button: married persons and persons about to marry stand in a confidential relationship and must deal fairly with each other. That is not the posture of arm’s-length commercial parties, and drafting as though it were is a mistake.
Voluntariness. The question is whether each spouse had a meaningful choice. Button lists the factors a court should consider: whether each party was represented by independent counsel, whether each had adequate time to review the agreement, whether the parties understood the terms and their effect, and whether they understood their financial rights in the absence of an agreement. The last of those is the one most often missing in practice. A spouse who signs without ever being told what the default rules would have given her has a real argument that the choice was not meaningful.
Substantive fairness. This is, in the court’s own word, “amorphous,” and it is decided case by case. Two guardrails from Button. An agreement need not divide property the way a divorce court would — if the parties could do only what a court would do, the right to contract would be meaningless, and an agreement preserving premarital property for children of a prior marriage is a legitimate objective. But the agreement “should in some manner appropriate to the circumstances of the parties take into account that each spouse contributes to the prosperity of the marriage by his or her efforts.” An agreement that gives one spouse nothing for decades of contribution is the one in trouble.
And an unequal result is not, standing alone, an unfair one. Button is explicit: an agreement fair at execution is not unfair at divorce merely because applying it produces a division that is unequal or that a court would not have ordered.
Changed circumstances: the prong that defeats real agreements
The exception that swallows a great deal is this one. If there are significantly changed circumstances after execution, and the agreement as applied at divorce no longer comports with the reasonable expectations of the parties, an agreement that was fair when signed may be unfair at divorce. Button, 131 Wis. 2d 84.
For a change to count as uncontemplated, the event “must not have been reasonably foreseen by the parties prior to or at the time of the making of the agreement.” Warren v. Warren, 147 Wis. 2d 704, 708-09 (Ct. App. 1988), as quoted in Krejci v. Krejci, 2003 WI App 160. Foreseeable life events — one spouse leaving the workforce, a business growing, children arriving — are the sort of thing the parties were supposed to plan for at the outset.
Two recurring fact patterns do count. The first is neglect: in Brandt v. Brandt, 145 Wis. 2d 394 (Ct. App. 1988), the agreement was “so long forgotten or ignored by the parties” while their finances were managed to everyone’s satisfaction in the interim, and it was never resurrected or discussed during the parties’ estate planning, nor did they implement separate estate plans.
The second is commingling, and it is the most practically important sentence in this entire body of law. From Brandt, quoted with approval in Krejci:
More importantly, the commingling of the parties[‘] assets and the resultant inability to trace makes a meaningful enforcement of the marital agreement impossible. A party’s request to enforce a marital agreement carries with it, we conclude, a concomitant responsibility to trace the property such that a reliable identification and valuation of the assets governed by the agreement can be made.
Krejci is the cautionary tale. The husband had inherited a lakeside resort before the marriage, and the prenuptial agreement excluded it from the marital estate. The court of appeals affirmed the trial court’s refusal to enforce the agreement on the third Button prong — unfair not at its inception but at the time of the divorce — and affirmed an award to the wife of part of the resort’s appreciated value. The husband’s argument that the resort had been kept entirely separate did not save him; an asset may be part separate property and part marital estate subject to division. Haldemann v. Haldemann, 145 Wis. 2d 296 (Ct. App. 1988).
The lesson is operational rather than legal. An agreement is only as good as the bookkeeping that follows it. Separate accounts, clean titling, documented sources of funds, and a paper trail that a court can actually follow years later are what make the document enforceable. A beautifully drafted agreement sitting in a drawer above twenty years of joint accounts is close to worthless.
Drafting for the wrong event
One more failure mode, and it is entirely avoidable. In Levy v. Levy, 130 Wis. 2d 523 (1986), the premarital agreement was intended to apply at death. The circuit court used it to divide property at divorce. The supreme court reversed, holding as a matter of law that the agreement “had nothing to do with the situation covered by that statute — property division upon divorce,” and remanded for a property division made without reference to the agreement at all.
Death and divorce are different events, and an agreement that addresses one does not silently address the other. Section 766.58 (3) (c) permits an agreement to govern disposition “upon dissolution or death,” and the word “or” is a drafting instruction. If the agreement is meant to govern both, it has to say both.
A related point of vintage: § 767.61 (3) (L) — formerly § 767.255 (11) — applies to agreements executed before the provision was enacted. Hengel v. Hengel, 122 Wis. 2d 737 (Ct. App. 1985). An old agreement is not immune from review simply because it predates the statute.
Maintenance is a separate question
Section 766.58 (3) (d) permits an agreement to modify or eliminate spousal support, subject to the floors in sub. (9) described above. But notice the text of the divorce-side provision: § 767.61 (3) (L) makes binding a written agreement “concerning any arrangement for property distribution.” By its terms, that statutory binding effect is about property division. Maintenance is governed by § 767.56, which has its own factors and its own case law.
The practical consequence is that a couple who assume a single signature has disposed of both property and support should not assume it. Whether and to what extent a maintenance waiver binds a Wisconsin divorce court is a distinct question that turns on the agreement’s language and the parties’ circumstances, and it is one to put to counsel directly rather than infer from a property-division clause. Our article on spousal maintenance in Wisconsin covers what a court weighs when it decides the question on the merits.
The statutory form agreements
Chapter 766 supplies two fill-in-the-blank instruments for couples whose goal is simple classification rather than a bespoke arrangement.
Under § 766.587, a statutory individual property classification agreement classifies all property of the spouses — presently owned and later acquired, until the agreement terminates — as the individual property of the owner, with ownership determined as if it were December 31, 1985. The form is set out in § 766.587 (7). Under § 766.588, a statutory terminable marital property classification agreement runs the other direction, classifying the spouses’ property as marital property, with the form at § 766.588 (9). In both cases, § 766.58 otherwise applies, and persons intending to marry may execute one that takes effect on the marriage or determination date.
These forms are genuinely useful for the narrow job they do. They are not a substitute for an agreement addressing a business, a blended family, a disparity in premarital wealth, or an intended disposition at death — and neither form is drafted with the Button analysis in mind, because neither form can supply the disclosure and deliberation that Button requires.
Timing traps after a death
If an agreement is to be challenged after a spouse dies, the clock is short. Under § 766.58 (13) (b), if an estate administration proceeding is filed, no action concerning a marital property agreement may be brought later than 6 months after the inventory is filed under § 858.01 — with a further 6 months running from an amended inventory as to new information it contains. If no estate proceeding is filed, the deadline is 8 months after the death. The court may extend the 6-month period for cause, but only if the motion is made within that period. § 766.58 (13) (c). Separately, § 766.58 (13) (a) tolls any statute of limitations applicable to a provision effective upon or after dissolution or death until that event occurs.
What actually makes one hold up
Strip away the case names and the enforceable agreement has a consistent profile. Both parties disclosed in writing, with actual numbers rather than categories. Both had real time — not the week of the wedding. Each had independent counsel, or the decision to proceed without it was informed and documented. Each understood what the default rules would have provided, so that the choice to depart from them was a choice. The substantive terms acknowledge in some form that both spouses will contribute to the marriage. The document addresses divorce and death separately and says which it means. And after signing, the parties actually lived by it — separate property stayed separate, traceable, and titled correctly.
The agreements that fail rarely fail for exotic reasons. They fail because the disclosure was a gesture, because one party was handed the document days before the ceremony, because the drafting addressed the wrong event, or because twenty years of commingling made the agreement unenforceable as a matter of arithmetic long before any court looked at it.
Because a marital property agreement classifies property under ch. 766 while a divorce court divides it under ch. 767, anyone considering one should understand both frameworks. Our article on dividing property in a Wisconsin divorce explains what the divorce court does in the absence of an agreement — which is precisely the baseline any agreement is measured against.
Talk to a New Berlin family law attorney
Carson Law Office handles family law matters for clients throughout New Berlin, Waukesha County, Milwaukee, West Allis, Wauwatosa, and the surrounding communities. If you are considering a marital property agreement before a marriage, revisiting one during a marriage, or facing one in a divorce, call (262) 860-8932 or contact us here.
This article provides general information about Wisconsin marital property agreements and is not legal advice. Reading it does not create an attorney-client relationship. Statutes and case law change, and whether any particular agreement is enforceable depends on its terms, the circumstances of its execution, and the record made in court; for advice about your own situation, speak with a licensed Wisconsin attorney.