Prenuptial Agreements and Marital Planning

What a Prenuptial Agreement Actually Does

A prenuptial agreement — sometimes called a premarital agreement or simply a "prenup" — is a contract between two people who intend to marry. It takes effect the moment they do. Its core function is to establish, in advance, which assets are each spouse's separate property and which will become marital property subject to division in a divorce or settlement at death.

Separate property generally refers to assets one spouse owned before the marriage, plus inheritances and gifts received during it, though the rules differ by state. Marital property is typically everything acquired together during the marriage. Without a prenup, a court applies the default rules of the state in which the couple lives — and those rules may distribute assets in ways neither family anticipated.

For families with substantial wealth, the stakes are meaningful. A single divorce can trigger forced sales of illiquid assets, disrupt a family business, or dilute ownership in structures that took decades to build. A prenup does not guarantee any particular outcome, but it creates a framework the parties themselves designed rather than one a judge will invent later.

What These Agreements Typically Address

A prenuptial agreement can cover a wide range of financial matters. Families sometimes consider including provisions that address:

• Which premarital assets remain separate property and how they will be treated if they grow in value during the marriage
• How inherited assets — including future inheritances — will be characterized, especially if they are commingled with joint accounts
• Ownership and management rights in a family business, partnership, or operating company
• Spousal support (alimony) terms, including whether it will be paid, for how long, and under what conditions
• How debt each person brings into the marriage will be handled
• Rights to certain estate planning distributions, which may interact with existing wills and revocable trusts

What a prenup generally cannot do is set terms for child custody or child support — courts retain authority over those matters regardless of any agreement between parents.

Trusts as the Deeper Layer of Protection

For inherited wealth in particular, a prenuptial agreement is often the second line of defense, not the first. A properly structured and maintained irrevocable trust — one established by a parent or grandparent, not by the beneficiary spouse — can place assets beyond the reach of divorce proceedings without relying on the prenup at all. This is because the beneficiary typically does not own trust assets; the trustee holds them for the benefit of the beneficiary.

The critical word is "maintained." Trustees and beneficiaries sometimes undermine trust protection without realizing it — by commingling trust distributions with marital accounts, for example, or by using trust assets to pay for marital expenses in ways that blur the line between separate and marital property. Asset protection trusts and dynasty structures may offer additional layers, depending on how they are drafted and where they are domiciled.

Families sometimes find it useful to have both: the prenuptial agreement addressing the couple's own assets, and the trust structure protecting inherited or family wealth that was never the couple's to begin with. A qualified attorney should evaluate how these interact under the laws of the relevant state.

Enforceability: Process Matters as Much as Substance

Courts have overturned otherwise reasonable prenuptial agreements because of how they were negotiated, not what they said. Enforceability generally depends on several factors that attorneys evaluate:

• Independent counsel. Each party should have their own attorney reviewing the agreement. An agreement presented without time to obtain counsel — or signed with both parties using the same lawyer — raises serious enforceability concerns.
• Full financial disclosure. Both parties should have a clear picture of what the other brings to the marriage. Agreements signed without adequate disclosure of assets, income, and liabilities are vulnerable to challenge.
• Timing. An agreement presented one week before the wedding — or the night before — may be challenged as signed under duress. Families and advisers often work toward execution weeks or months in advance of the ceremony.
• Fairness standards. Some states allow courts to revisit agreements that were fair when signed but have become dramatically one-sided over time. Others treat the agreement as essentially final if the process was clean.

Because enforceability standards vary meaningfully from state to state — and because couples may move during a marriage — a qualified family law attorney must review any specific agreement. This is not a document appropriate for template-based drafting.

The Emotional Choreography

No section on prenuptial planning is honest without acknowledging what it actually feels like. Asking a future spouse to sign a financial contract before the wedding can feel like a statement of distrust, a prediction of failure, or an imposition from the older generation. The emotional stakes are real, and families who handle this clumsily sometimes cause lasting damage to relationships — including the one they were trying to protect.

A few patterns tend to make the process less fraught. Framing the conversation as a mutual planning exercise — not a demand — changes its character. Families who have done the work of inheritance conversations earlier in the next generation's development often find their children better prepared to understand why the agreement exists. When the rationale has been discussed openly over years, the prenup becomes a formality rather than a surprise.

The timing of who raises the topic also matters. Many advisers suggest that the request come from the wealth-holding party directly, not from a parent or family office — which can feel to the incoming spouse like being negotiated against by an institution rather than a person. Some families find it useful to have a family governance framework, like a family constitution, that already articulates wealth-protection expectations as a matter of family policy rather than personal suspicion.

Postnuptial Agreements

A postnuptial agreement — executed after a marriage has already begun — serves a similar function to a prenup but faces a somewhat more complex legal environment in many states. Courts apply extra scrutiny because the parties are no longer arm's-length strangers but spouses with existing legal obligations to each other.

Postnups are worth knowing about in several situations: when a couple married without any agreement and significant wealth entered the picture later (through a business exit, inheritance, or other liquidity event), when circumstances changed in ways the original agreement did not anticipate, or when a couple is working through difficulties and wants to clarify financial terms as part of reconciliation planning.

The same enforceability principles apply — independent counsel, full disclosure, absence of duress — but a qualified family law attorney familiar with the applicable state's treatment of marital agreements is particularly important here, because the law governing postnups is less uniform than that governing prenups.

Questions Worth Raising with Counsel

Families and their advisers sometimes find it useful to come to legal consultations with a prepared set of questions. A few that arise frequently in this context:

• How does this state treat inherited assets that are later commingled with marital property?
• Does the agreement need to be updated if the family moves to a different state — or if the couple moves abroad?
• How should trust distributions be handled by the beneficiary spouse to preserve their separate-property character?
• What happens to the prenup if the couple has children — does anything change automatically?
• How does this agreement interact with existing estate planning documents, including irrevocable trusts established by earlier generations?
• Should the agreement include a sunset clause — a provision under which certain terms expire after a defined number of years of marriage?

None of these questions has a universal answer. They are starting points for a conversation with qualified legal and financial professionals, not conclusions.