Marriage agreements are often discussed like they’re just about “protecting assets,” but that framing leaves out a lot. A prenuptial agreement is typically signed before marriage. A postnuptial agreement is typically signed after the wedding. In both cases, the document can shape how property, debt, support, and legal costs may be handled later if the relationship changes. The details often matter more than the label.
That is one reason many couples start with a broader overview of how these agreements are usually reviewed for fairness, disclosure, and enforceability before focusing on any single clause.
In this post, you’ll learn 10 clauses that commonly appear in prenups and postnups, what each one often tries to do, where problems can arise, and why careful drafting can matter so much. While state law varies, courts often look closely at voluntariness, financial disclosure, and whether the agreement was unconscionable when signed or when enforced. The Uniform Premarital and Marital Agreements Act was created in part to address inconsistent standards across states, and the American Bar Association notes that enforceability disputes often center on property division, support, custody-related issues, and attorney’s fees. The timing also matters: Census data shows Americans are marrying later than in prior generations, which often means more people are entering marriage with established careers, retirement savings, equity, or business interests already in place, as reflected in recent Census marriage data and ACS estimates on first-marriage age.
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A separate property clause usually says what each spouse owns individually before the marriage and what remains individually owned during the marriage.
This is often the backbone of the agreement. It may list real estate, brokerage accounts, retirement funds, family inheritances, business interests, vehicles, collectibles, and other assets. In some agreements, appreciation on separate property also stays separate. In others, appreciation becomes a point of negotiation, especially if marital labor or marital money contributed to the increase.
This clause can become especially important when one person enters the marriage owning a home, holding equity in a startup, expecting a family inheritance, or managing substantial investment accounts. Without clear language, the line between separate and marital property can become blurry over time.
Courts often care about accurate financial disclosure here. If an asset is omitted, undervalued, or vaguely described, that omission can later become part of an enforceability challenge. Under the ABA’s discussion of prenups, agreements commonly address premarital property and the characterization of property acquired during marriage. The Uniform Law Commission’s act likewise reflects how state-to-state variation has created uncertainty around enforcement.
A lot of people assume “separate property” automatically covers everything with one person’s name on it. In practice, that is often too simplistic. Titling matters, but so do commingling, tracing, contributions during marriage, and local law. An attorney may help determine whether the wording actually matches the couple’s intent.
If the first clause defines what stays separate, the marital property clause often defines what is shared.
This part may explain whether income earned during the marriage is marital, whether joint purchases are shared equally, and whether appreciation in certain assets gets treated as marital even if the original asset started as separate property. In community property states, this analysis can intersect with different default rules than in equitable-distribution states, which is one reason broad assumptions can become risky. The IRS also separately recognizes the significance of community property systems in its community property guidance.
This clause often becomes more complicated when couples: