What Is a Postnuptial Agreement in Missouri?
It is a written contract between two people who are already married, signed while the marriage is intact, that decides in advance how property, debt and financial support would be handled if the marriage ended.
Same idea as a prenuptial agreement. Different timing, and in Missouri that timing changes which body of law applies.
The question what is a postnuptial agreement has a short answer and a longer one. Missouri recognizes three separate documents, and almost everything written online blurs them together.
- The prenuptial agreement. Signed before the wedding. Missouri courts also call it an antenuptial agreement, and the two words mean the same thing
- The postnuptial agreement. Signed during a marriage that both people intend to continue. This is the one this page is about
- The separation agreement. Signed when the marriage is already ending, and expressly authorized by Section 452.325 RSMo
The distinction matters more than it sounds. A separation agreement has a statute behind it. A postnuptial agreement does not, and Missouri has no premarital agreement act either, because Senate Bill 998 in 2010 would have created Sections 452.615 through 452.660 and those numbers are still vacant in Chapter 452.
It rests on decisions from the Missouri Court of Appeals, which is a thinner foundation and a real thing to know before you sign one. Our page on legal separation covers the third document in that list.
Why Would a Married Couple Sign One?
Because something changed after the wedding that the couple wants to put in writing while they still agree about it.
Nobody signs a postnuptial agreement on a normal Tuesday. There is almost always a specific event behind it.
- A business started or bought during the marriage. The owner wants the company to survive intact, and the other spouse wants their contribution recognized rather than argued about later
- An inheritance received or expected. Separate property can lose its character through commingling, and an agreement can settle the question in advance
- A second marriage with children from the first. Both people want to protect what each child was always going to receive
- One spouse leaving work. The person stepping back from a career often wants that decision papered rather than assumed
- A prenup that never got signed. The wedding came faster than the paperwork did, and the couple still wants the terms
- A rough patch both people are trying to get past. This one is the most common and the most delicate, and it is the version courts look at hardest
Anyone asking what is a postnuptial agreement while in that last situation is asking about a document with its own name in family law, and it is covered further down.
What Can a Postnuptial Agreement Cover?
Property, debt and spousal support, which covers most of what a divorce fights about.
A workable agreement usually addresses several things at once.
- Which assets stay separate and which are treated as marital, including a business, a professional practice, an inheritance or an investment account
- How growth in the value of a separate asset is treated, which is where most owner cases actually turn
- Who is responsible for which debts
- Whether spousal maintenance would be paid, and on what terms
- What happens to the house
- Rights in each other’s estate at death, which is a separate question from divorce and is covered below
For context on what Missouri would do without an agreement, our FAQ on dividing marital property explains why equitable has never meant equal.
Can It Decide Custody or Child Support?
No, and the statute says so twice.
Section 452.325.2 RSMo makes the terms of an agreement binding on the court “except terms providing for the custody, support, and visitation of children.” Section 452.325.6 RSMo repeats the carve out when it comes to limiting later modification.
Two adults can contract about their own money. They cannot contract about a child’s right to support or a court’s obligation to decide custody on the child’s best interests. An agreement that tries anyway does not usually fail as a whole. The offending term simply has no effect, and the court decides child support and custody the way it would have anyway.
Is a Postnuptial Agreement the Same as a Separation Agreement?
No, and the difference is which law governs.
A separation agreement is made attendant upon a separation or a dissolution, meaning the marriage is ending and both people know it. Section 452.325 RSMo authorizes it directly and gives it a review standard, which is that its terms bind the court unless the court finds the agreement unconscionable after considering the economic circumstances of the parties.
A postnuptial agreement is made while the couple intends to stay married. There is no statute for it. What exists instead is case law.
The practical consequence is worth stating plainly. Two documents that look nearly identical on paper can be reviewed under different frameworks depending on what the couple intended when they signed. That is not a technicality, it is the first question a court asks.
What Does Missouri Require for the Agreement to Count?
Missouri applies the same standard it applies to prenuptial agreements, which is that the agreement must be entered into “freely, fairly, knowingly, understandingly and in good faith and with full disclosure.”
That phrasing comes from Lipic v. Lipic, 103 S.W.3d 144 (Mo. App. E.D. 2003), and it is doing more work than it looks like.
Read the list as six separate things a challenger can attack, because that is how it gets used.
- Freely. No coercion, no ultimatum delivered in a way that left no real choice
- Fairly. The process was fair, which is a different question from whether the deal was generous
- Knowingly. Each person knew what the document was
- Understandingly. Each person understood what it did, which is why plain drafting matters more than elegant drafting
- In good faith. Neither person was working an angle the other could not see
- With full disclosure. Each person knew what the other had, and Missouri’s version of full disclosure is more forgiving than the phrase suggests
Beyond that, put it in writing and sign it. An oral understanding about who keeps the business is not an agreement, it is a memory, and two people rarely have the same one.
Does Missouri Actually Enforce These?
Yes, and Missouri said so in a case where the challenging spouse argued the exact opposite.
In Lipic the wife’s position was that an agreement signed to keep a marriage together is different in kind and should be void as against public policy. The Eastern District, which covers St. Louis City and St. Louis County, answered directly that “we do not believe that post-nuptial agreements are against public policy in Missouri.”
The one thing to carry away is that the common assumption, which is that Missouri will not honor an agreement signed after the wedding, is not what the reported law says. What is fair to add is that the body of authority behind a postnuptial agreement is thinner than the body behind a prenuptial one, and thin authority is not the same thing as adverse authority.
What Is a Reconciliation Agreement?
It is a postnuptial agreement whose stated purpose is saving the marriage, and Missouri does not treat it as a separate legal category.
The couple is in trouble, one or both want to stay, and the agreement is part of what makes staying possible.
Lipic itself came out of circumstances like these, which is why the court’s reasoning ran to the pressure involved. Its answer was that “the pressures involved when one party to an ante-nuptial agreement wants to get married are at least similar to the pressures involved when one party wants the marriage to continue.” In other words, pressure is present in both situations and its presence alone is not what invalidates an agreement.
There is no separately reported Missouri body of law for reconciliation agreements. They collapse into the postnuptial category and get reviewed the same way. What is different is the practical setting. These get signed at the least calm moment in a marriage, which makes the fairness of the process the thing most worth being careful about.
Can a Postnuptial Agreement Waive an Inheritance Right?
Yes, and this is the one place where a Missouri statute expressly contemplates a document signed after the wedding.
Section 474.220 RSMo provides that a surviving spouse’s right of election “may be waived before or after marriage by a written contract, agreement or waiver signed by the party waiving the right of election, after full disclosure of the nature and extent of the right, if the thing or the promise given to the waiving party is a fair consideration under all the circumstances.”
Note the three conditions. In writing and signed. After full disclosure. For fair consideration.
Note also what the statute is not. It governs the elective share, meaning what a surviving spouse can claim against a will. It is not a premarital agreement act and it does not set the rules for dividing property in a divorce. It is worth knowing because the phrase before or after marriage is a legislative acknowledgment that agreements between spouses exist, which is the same instinct the court followed in Lipic.
What Does a Postnuptial Agreement Not Do?
Four things, and being clear about them is what keeps an agreement from becoming a grievance later.
It does not end the marriage. It is a contract about terms, not a divorce, and signing one changes nothing about your marital status.
It does not bind a court on anything involving your children. Custody, support and visitation stay with the court under Section 452.325.2 RSMo.
It does not survive on its own strength. Missouri courts review these agreements, and the review looks at how the agreement was made as much as what it says.
And it does not remove the need for records. Property acquired during the marriage is presumed marital under Section 452.330 RSMo, and an agreement that says a business stays separate still leaves a question about growth in value during the marriage, and the answer to that question lives in financial records rather than in the document. If a company is involved, our page on divorce for business owners covers what those records need to show, and our high net worth divorce page covers larger estates.
Who Can Help With a Postnuptial Agreement in Missouri?
Anyone asking what is a postnuptial agreement is usually asking it because something already changed, and a postnuptial agreement is a planning document, which means the best time to look at one is well before anybody needs it.
Bardol Law Firm practices only family law and drafts and reviews marital agreements for couples in St. Louis County, St. Louis City, St. Charles County and Jefferson County. You can read more about prenuptial agreements in Missouri, about property and asset division if a case is already underway, and the rest of our family law questions and answers.
You should not have to chase your attorney for basic updates. Every client here has a named paralegal on the file, and we generally return calls within one business day.
Family Law, Simplified.
If you are thinking about putting something in writing, the earliest conversation is the most useful one. Contact Bardol Law Firm or call 314.918.0100 to talk through what your options actually look like.
This page is general information about Missouri law and is not legal advice. Every case turns on its own facts. The choice of a lawyer is an important decision and should not be based solely upon advertisements.