Divorce can turn a marital agreement into the center of the entire case. What looked clear and settled years earlier may suddenly become the subject of arguments about pressure, fairness, disclosure, timing, or whether the document covers what one spouse says it covers. That is often true with both prenuptial and postnuptial agreements.
In general terms, marital agreements are designed to bring predictability to property division and, in some cases, spousal support. But enforceability is rarely just about whether both spouses signed. Courts often look closely at how the agreement was negotiated, what each person knew at the time, and whether the terms cross lines that state law does not allow. The American Bar Association notes that premarital agreements usually address property division and alimony, while terms affecting child support or custody generally are not enforceable in the same way because children’s rights are treated differently under the law (ABA overview).
In this post you’ll learn how challenges and defenses to marital agreements often work during divorce, what facts tend to matter most, and why finding a lawyer with documented experience in highly-similar matters can make a major difference when a contract is either under attack or being defended.
<aside> 💡 Scroll to the bottom for every post in this series.
</aside>
A marital agreement can affect who keeps what, whether appreciation in a business stays separate, how debts are handled, and whether one spouse may seek support. Without an enforceable agreement, default state law usually controls those issues at divorce (ABA overview). That alone explains why these documents are so often litigated.
Marital agreements are also more common than many people assume. The ABA has cited studies suggesting that roughly 10% of married couples have entered into either a premarital agreement or some kind of post-marital agreement dealing with property distribution if they separate or divorce (ABA family law article). At the same time, divorce remains a significant reality in the United States. The CDC reports 672,502 divorces and a divorce rate of 2.4 per 1,000 population based on provisional 2023 data from 45 reporting states and D.C. (CDC FastStats).
That combination creates a practical result: many divorces involve a written agreement that one side wants enforced and the other wants limited or set aside.
If you want a broader foundation on how courts look at enforceability, disclosure, fairness, and common attacks on these contracts, it may help to start with this guide on how courts evaluate these marital contracts.
The phrase “marital agreement” can describe different documents, and that distinction matters.
A prenuptial agreement is signed before marriage. In many states, statutes based on the Uniform Premarital Agreement Act or the newer Uniform Premarital and Marital Agreements Act help shape the legal framework, though states do not all follow the same rules or wording (Uniform Law Commission PMAA, Uniform Law Commission UPAA, Nolo overview).
A postnuptial agreement is signed after marriage. Courts often scrutinize postnups closely because spouses already owe one another heightened duties in many states, and the context can raise questions about leverage, financial dependence, or pressure. The ABA has noted that the law on postmarital agreement validity continues to develop in many jurisdictions (ABA Family Advocate Spring 2024).
These agreements commonly address: