What a prenup needs to cover, and what the law already protects

Most people assume what they owned before the wedding, and anything they inherit, is theirs automatically. In most states that is roughly true. In fourteen it is not — and in almost every state it stops being true the moment the money is mixed, retitled or grown with marital effort. A prenup is how two people decide those questions calmly, in advance, instead of in front of a judge.

The short version9 points · tap one to jump to it

1. Your state: is it already protected without a prenup? — “Protected” means the law sets it aside to the spouse who owns it.
2. “Protected” does not mean untouched — Even in the states marked protected, separate property is lost in the same handful of ways.
3. Inheritances and trusts: do you have to put them in? — Because the answer varies so much, the safe course is to name the trust in the agreement, say whether distributions you receive stay separate, and say what happens to anything bought with them.
4. What makes a prenup fair — “Fair” means two different things, and a good agreement needs both.
5. What a good prenup covers — A prenup cannot decide custody or reduce child support.
6. An easier way to part — The most useful thing a prenup does is not protect money.
7. The three that catch people — Almost every prenup conversation starts with the same three facts: an inheritance coming, a place one of you already owns, and money from a parent.
8. What is usually missing from the list — People arrive with the assets they can see.
9. Questions to settle together

In this subject 10

Your state: is it already protected without a prenup?

This is the default — what happens at divorce if you have no agreement. “Protected” means the law sets it aside to the spouse who owns it. “Court can divide” means a judge may give some of it to the other spouse. Read the last two columns before relying on the first two.

† In these states the rule comes from court decisions rather than a statute that defines separate property. — means we could not confirm it from a primary source and would rather say so than guess. Checked against each state’s own statute, 20 September 2026. This is the default at divorce, not at death, which follows different rules.

“Protected” does not mean untouched

Even in the states marked protected, separate property is lost in the same handful of ways. Every one of them is ordinary married life, which is why people are surprised:

1. Mixing it. An inheritance deposited into the joint account is, in many states, no longer traceable — and untraceable separate property is treated as marital.
2. Retitling it. Putting the house you owned before the marriage into both names, or retitling an inherited home jointly, can make it marital. In Florida that is written into the statute.
3. Paying for it with marital money. When the mortgage on your premarital home is paid down from your salaries during the marriage, several states give the marriage a share of the house.
4. Growing it with effort. In many states passive market growth stays yours, but growth from either spouse’s work is marital. In Colorado and Pennsylvania all the growth during the marriage is marital.
5. The income it throws off. In Texas, Idaho and Louisiana the income from separate property — rent, dividends, interest — is community property unless you agree otherwise in writing.

A prenup can settle every one of these in advance: what stays separate, whether the growth and income stay with it, and what happens if the two are mixed.

Inheritances and trusts: do you have to put them in?

You do not have to. There are four good reasons to anyway:

• You live in a state where a court can divide it. Then leaving it out protects nothing.
• You want the growth and income to stay with it. The default often protects the inheritance and not what it earns.
• You expect one later. A prenup can say how a future inheritance will be treated, which is far easier to agree before anyone has died.
• You want no argument about what it was. Listing it, with its value on the day you signed, removes the hardest part of any later dispute — proving what was separate to begin with.

Trusts. Whether an interest in a family trust is treated as property at all usually turns on how much right you have to it — a fixed right to payments is treated very differently from payments made at a trustee’s discretion, and Vermont’s statute expressly excludes an inheritance that has not vested and can still be changed. Because the answer varies so much, the safe course is to name the trust in the agreement, say whether distributions you receive stay separate, and say what happens to anything bought with them.

What makes a prenup fair

“Fair” means two different things, and a good agreement needs both.

Fair enough to be enforced. Courts throw out prenups that were not signed voluntarily, that were signed without honest disclosure of what each person owned and owed, or that were unconscionable — so one-sided that no reasonable person would have agreed. Some states also ask whether it has become unfair by the time of the divorce. That half of the question has its own pages: the four ways a prenup dies and how one is challenged.

Fair in substance. An agreement can be perfectly enforceable and still leave one person with nothing after twenty years. The signs of a fair one:

• It protects both people, not one. Each side’s separate property is listed, and so is each side’s debt.
• It changes with time. What is reasonable after two years is not reasonable after twenty. Fair agreements step up with the length of the marriage, or end altogether after a set number of years.
• It accounts for the person who steps back. If one of you leaves work to raise children, a fair agreement says what that is worth rather than pretending it did not happen.
• It shares what you build together. Protecting what each of you brought in is reasonable. Carving out everything either of you earns during the marriage usually is not.
• Both people had time and the full picture. Signed well before the wedding, with every account on the table.

What a good prenup covers

Every prenup is different, but a complete one works through the same list:

1. A schedule of what each of you has and owes today, with values. This is the disclosure, and without it the rest can fall.
2. What stays separate — premarital property, inheritances, gifts, trust interests — and whether its growth and income stay separate too.
3. What happens when separate and marital money mix, including a premarital home whose mortgage you pay down together.
4. The home you will live in: whose it is, and what the other person gets if it was one person’s before the marriage.
5. Retirement accounts and pensions, including what was earned before and during the marriage.
6. A business either of you owns or starts, and whether its growth is shared.
7. Debt: who is responsible for what each brought in, and for what is borrowed during the marriage.
8. Spousal support — the clause that varies most by state. Which states limit it.
9. Death as well as divorce, if you want the agreement to cover what each inherits from the other.
10. A review date — a point, often a birth or an anniversary, at which you both look at it again.

An easier way to part

The most useful thing a prenup does is not protect money. It is removing the fight. An agreement can set out the mechanics of separating, so that if the marriage ends the hardest decisions are already made:

• Who stays in the home, and for how long, and how the other person is bought out — including how the price is set.
• A formula instead of a negotiation for anything you agree to share, so nobody has to argue about the number.
• Mediation before litigation, so the first step is a conversation rather than a filing.
• Who pays for what while it is happening — the mortgage, the insurance, the separate rent.
• Plain language. An agreement both of you can read is one both of you can follow.

The three that catch people

Almost every prenup conversation starts with the same three facts: an inheritance coming, a place one of you already owns, and money from a parent. Each of them has a trap that the agreement is the only place to fix.

1. An inheritance you will receive during the marriage

In most states an inheritance is separate property the moment it lands, even without a prenup. It stops being separate in four ordinary ways, and none of them feels like a decision at the time:

• Mixing. It goes into the joint account “for now.” Later, tracing it is your job, and bank statements do not go back forever.
• Retitling. A parent’s house is put into both names, or refinanced into both names. In most states that is a gift to the marriage, and it is very hard to undo.
• Growth and income. Several states treat the increase in value, or the income it throws off, differently from the asset itself. Protecting the house does not automatically protect the rent.
• Spending it on the family. Using inherited money to pay down the joint mortgage is usually treated as a gift to the marriage unless the agreement says it comes back.

Two things worth knowing that most people are not told. A prenup is also where a spouse waives the right to claim against the other’s estate at death — the elective share — which is usually what a parent’s estate planner actually cares about. And in fourteen states a court can divide separate property anyway, which is exactly the situation the agreement exists to close.

If your parents have not done it already, ask them whether the inheritance can come through a discretionary trust rather than outright. A trust protects what a prenup cannot, and the two together are stronger than either alone.

2. Selling the apartment you own and putting it into a house in both names

This is the one that costs the most money and gets the least thought. Putting separate money into a jointly titled home is presumed, in most states, to be a gift to the marriage. The deed says both names; the down payment came from one person; without an agreement the default answer in many states is that it is all marital.

So the agreement has to say the down payment comes back off the top. Then it has to answer the question almost nobody asks first:

• Dollars back, or a share back? Say you put $200,000 down on an $800,000 house — a quarter of it. If the house is worth $1.2 million when you part, “your $200,000 back” returns $200,000. “Your 25%” returns $300,000. Both are reasonable. They are not the same, and the difference only grows.
• What happens if you refinance, or sell and roll the money into the next house. Protection that does not survive a move is protection with an expiry date.
• Marital money paying the mortgage. Every payment made from income earned during the marriage builds equity that is usually marital, however the deposit was funded.
• Who keeps it, and at what price. Who has the first option to buy the other out, how the value is set, and who pays the mortgage, taxes and insurance while it is being sorted out.

3. The money your parents are giving you both

You want it back if the marriage ends. That is a reasonable thing to want, and the prenup is not, by itself, how you get it. A prenup binds the two of you. It does not make your parents a creditor.

• If they want it back in every scenario — divorce, death, bankruptcy, a judgment against either of you — it is a loan, and it needs to look like one: a signed promissory note, and a mortgage or deed of trust recorded against the house. A recorded lien follows the property. A promise between spouses does not.
• If it is a gift, the agreement should say whose. A check made out to both of you, or deposited into a joint account, is presumed a gift to both in most states. A gift to you alone, documented as such, is the version the prenup can protect.
• A loan that is never called in is treated as a gift by most courts. If it is a loan, it needs a payment schedule that somebody actually follows.
• Their side has tax paperwork. A large gift usually means a federal gift tax return for the giver, even when no tax is owed. That is their advisor’s job, not yours, but it is worth mentioning to them before the money moves.

What is usually missing from the list

People arrive with the assets they can see. These are the ones that turn up later:

• Growth and income on everything separate, not just the house. In Texas, Idaho and Louisiana the income from separate property is community property by default.
• Retirement accounts, equity and options that vest across the wedding date. A grant made before the marriage that vests during it is the classic split-the-difference fight.
• Debt. Student loans, a credit card, a business guarantee. Whose it is, and who is exposed to it.
• Spousal support. The single most contested clause. Some states will not enforce a complete waiver, and a formula tends to survive where a zero does not.
• Death, not only divorce. The elective share waiver, life insurance to back any promise made, and beneficiary designations, which override a will and are forgotten more often than anything else on this page.
• Moving. The agreement should name the law that governs it and be built to hold up in the states you might realistically live in.
• A sunset clause. Tempting, and double-edged: it removes the protection at exactly the point the assets are largest.
• The two things it cannot do. Custody and child support are the court’s to decide, whatever the document says.
• Record-keeping. The agreement is the rule; the paper trail is the proof. Separate money stays in separate accounts, and the statements get kept.
• How it is signed. Full schedules of what each of you owns and owes, separate lawyers, and weeks of daylight before the wedding. Agreements fail on that far more often than on what they say.

Questions to settle together

Before either of you drafts anything, these are the conversations that decide what the agreement says:

1. What does each of us own and owe today — all of it?
2. Is either of us likely to inherit, and do we want that treated differently?
3. Should what we each brought in grow separately, or should the growth be shared?
4. If one of us stops working to raise children, what should that be worth?
5. Should the agreement change the longer we are married, or end after a certain point?
6. Where will we live, and whose name will the home be in?
7. If it ends, who stays in the house and how is the other person paid?

Keep reading

• Prenups and postnups — how they work and the four ways they fail
• The prenup checklist — twelve months out to after the wedding
• Annotated prenup clauses
• Challenging a prenup or postnup
• Postnuptial agreements — if you are already married
• Who gets what — how property is divided when there is no agreement

General information about the default rules in each state, not advice about your agreement. The rules at death differ from the rules at divorce. If a state has changed its statute since 20 September 2026, tell us.