New York Prenuptial and Postnuptial Agreement Law (DRL § 236(B)(3)): Are They Enforceable?

A prenuptial agreement in New York is a contract two people sign before they marry to decide, in advance, how property and support would be handled if the marriage ends. A postnuptial agreement does the same thing, signed after the wedding. Both are enforceable in New York when done right, and both can be thrown out when not.

People sign these agreements years before they ever matter, then wonder whether the document will actually hold when it counts. The answer depends almost entirely on how it was made.

This page covers whether these agreements are enforceable in New York, the requirements for a valid one, what they can and cannot decide, and the grounds on which one gets challenged.

Are Prenuptial and Postnuptial Agreements Enforceable in New York?

Yes, when they meet the legal requirements. New York recognizes prenuptial and postnuptial agreements, and Domestic Relations Law § 236(B)(3) sets the formal rules they have to follow. A properly made agreement can control how property is divided and how maintenance is handled, and a court will generally enforce it.

That said, “generally enforce” is not “always enforce.” These agreements are scrutinized more closely than ordinary business contracts because they are signed between people in a relationship of trust. An agreement that was rushed, hidden, or one-sided is the kind that gets attacked later.

What Are the Requirements for a Valid Prenuptial Agreement in New York?

The form requirements are strict. Under Domestic Relations Law § 236(B)(3), the agreement must be:

• In writing: an oral agreement about marital property does not count.
• Signed by both parties: each person has to sign.
• Acknowledged: signed with the same formality as a deed, before a notary, so the signatures are formally proven.

Beyond the form, the circumstances matter. Full and fair financial disclosure, separate independent counsel for each person, and enough time to review the agreement before signing all make an agreement far more durable. None of those is an absolute statutory requirement, but skipping them makes an agreement vulnerable. Our prenuptial agreement attorneys build each agreement with those protections so it can withstand a later challenge.

What Can and Cannot Go Into a New York Prenup or Postnup?

These agreements can decide the financial terms, but not the children’s. They can address how marital property is divided, how separate property is kept separate, whether either spouse pays maintenance and how much, and rights in each other’s estate. Couples with a business, premarital assets, or children from a prior relationship often use them to set those expectations in advance.

What they cannot do is bargain away what belongs to the child. Child custody and parenting time are decided by the best interests of the child at the time of the dispute, not locked in years earlier by contract, and child support cannot be waived or set below what the child is entitled to. A provision that tries to do either is unenforceable, even if the rest of the agreement stands.

On What Grounds Can a New York Prenuptial Agreement Be Challenged or Thrown Out?

A spouse who wants out of the agreement has to give the court a reason. The common grounds for challenging a prenuptial or postnuptial agreement in New York include:

• Improper execution: it was not signed and acknowledged the way the law requires.
• Fraud or hidden assets: one spouse concealed or misrepresented their finances.
• Duress or coercion: the agreement was signed under pressure, such as days before the wedding with no chance to review.
• Unconscionability or overreaching: the terms are so one-sided, and the process so unfair, that enforcing it would shock the conscience.

A court does not undo an agreement just because one spouse now regrets it or got a worse deal. The challenge has to show something was wrong with how the agreement was made or what went into it. Our prenuptial agreement attorneys both draft agreements to survive these attacks and represent spouses who have real grounds to challenge one.

What Is the Difference Between a Prenuptial and a Postnuptial Agreement in New York?

Timing. A prenuptial agreement is signed before the marriage and takes effect when the couple marries. A postnuptial agreement is signed during the marriage, by a couple who is already wed. Both must meet the same form requirements under Domestic Relations Law § 236(B)(3), in writing, signed, and acknowledged.

Postnuptial agreements sometimes draw closer scrutiny, because spouses already owe each other duties once married, so fairness in the process carries even more weight. Couples turn to a postnup when circumstances change, such as one spouse starting a business, receiving an inheritance, or wanting to settle financial questions without divorcing.

How Our Prenuptial Agreement Attorneys Draft Agreements to Hold Up in New York

A durable agreement is built, not boilerplate. Our prenuptial agreement attorneys handle the full financial disclosure, ensure each spouse has the opportunity for independent counsel, allow time for review rather than signing on the courthouse steps, and execute the agreement with the formality the law demands. We draft the terms clearly so there is no ambiguity to fight over later.

We prepare each agreement as if it will someday be read by a judge during a divorce, because the agreements that hold up are the ones built that way from the start.

Talk to Cedeño Law Group About a New York Prenuptial or Postnuptial Agreement

A strong agreement protects you. A weak one gives the other side a fight. Cedeño Law Group drafts and reviews prenuptial and postnuptial agreements built to hold up in New York. Call us before you sign anything.

Updated 2026. This page reflects New York’s law on prenuptial and postnuptial agreements under Domestic Relations Law § 236(B)(3) as in effect in 2026. It is general information, not legal advice.

For more laws, visit our New York Divorce and Family Laws page.