Few words in estate planning carry as much emotional baggage as “prenup.” It sounds like you’re planning for failure. Like you don’t trust the person you’re about to marry. Like you’re already thinking about the exit.
I get it. But that’s not what prenuptial and postnuptial agreements actually are — at least not in the estate planning context. They’re planning documents. They’re about making sure your wishes are clear, your assets go where you intend, and your family is protected in every scenario — including the ones nobody wants to think about.
What a prenup actually does
A prenuptial agreement is a contract between two people who are about to get married. It defines what happens to certain assets in the event of divorce or death. That second part is the one most people overlook.
In the estate planning context, a prenup can:
- Protect assets you’re bringing into the marriage (a house you owned before, an inheritance, a business)
- Define what counts as separate property vs. marital property
- Ensure that children from a prior relationship receive the inheritance you intend for them
- Coordinate with your trust to make sure your estate plan doesn’t contradict your marital agreement
- Protect a family business from being divided in a divorce
Notice that most of these aren’t about divorce at all. They’re about clarity, coordination, and making sure your estate plan works the way you designed it.
What a postnup is
A postnuptial agreement does the same thing as a prenup, but it’s signed after you’re already married. People often wonder if that’s even allowed — yes, it is, and it’s more common than you’d think.
You might want a postnup if:
- You got married without a prenup and your financial situation has changed
- One spouse received a large inheritance and wants to keep it separate
- One spouse started a business during the marriage
- You’re doing estate planning for the first time and realize your plan needs a marital agreement to work correctly
- You have a blended family and need to protect both your spouse and your children from a prior relationship
The blended family problem
This is where prenups and postnups become genuinely essential estate planning tools, not optional add-ons.
Here’s the scenario: you’re remarrying. You have children from your first marriage. Your new spouse has children from their first marriage. You both want to take care of each other, but you also want to make sure your respective children eventually receive their inheritance.
Without a marital agreement and a coordinated estate plan, this gets messy fast. If you leave everything to your new spouse, they could (intentionally or not) redirect those assets to their own children. If you leave everything to your children, your surviving spouse might be left without adequate support. State intestacy laws and spousal elective share rights add additional complexity.
A prenup or postnup, combined with the right trust structure, solves this: it defines what each spouse is entitled to, what passes to the children, and how the assets are managed. Everyone is protected. The plan works. No ambiguity.
A real pattern I see: A couple comes in for estate planning. Second marriage for one or both. They want to “take care of each other” but also protect their kids. Without a marital agreement, the trust alone may not be enough — because state law gives a surviving spouse certain rights that can override the trust. The prenup or postnup is the piece that makes the trust work the way it was intended to.
Who actually needs one
The stereotype is that prenups are for wealthy people protecting massive fortunes. In reality, the people who benefit most are often solidly middle-class families in specific situations:
- Second marriages with children from prior relationships — the most common and most important scenario
- Business owners — if your business is marital property, a divorce could force a sale or split
- People who received or expect to receive an inheritance — inheritance is usually separate property, but commingling it with marital assets can change that
- Couples with significantly different financial situations — one spouse has substantial assets or debt that the other doesn’t
- Anyone whose estate plan relies on specific asset distribution — if your trust says “this goes to my children,” a marital agreement reinforces that intention
How to bring it up
The hardest part of a prenup isn’t the legal work — it’s the conversation. Here’s what I suggest to clients:
Frame it as planning, not protection from your partner. “I want to make sure our estate plan works the way we intend, and our attorney recommended a marital agreement as part of that.” That’s true, it’s honest, and it positions the agreement as a tool that serves both of you — not as a signal of distrust.
For postnups, the conversation is often easier because you’re already married and you’re doing it as part of a broader planning exercise. “Our estate planning attorney flagged that we should consider this to make sure the trust works properly for our kids” is a perfectly reasonable thing to say.
Important note: Both parties should have independent legal counsel when signing a prenuptial or postnuptial agreement. This isn’t just good practice — it’s often required for the agreement to be enforceable.
How this fits into your estate plan
A prenup or postnup doesn’t replace your estate plan. It supports it. The marital agreement defines the boundaries. The trust operates within those boundaries. The will catches anything that falls outside. Together, they form a coordinated system where every piece reinforces the others.
If you’re considering a prenup or postnup, the most important thing is to make sure it’s coordinated with the rest of your estate plan. A marital agreement has tax implications. It affects beneficiary designations. It interacts with retirement account rules. The agreement and the estate plan need to speak the same language — otherwise one can inadvertently undermine the other.
Whether you’re getting married for the first time, remarrying, or simply want to revisit your existing arrangements, understanding how these documents work is the first step toward making sure your plan actually does what you intend.
