A New York postnuptial agreement is a written contract between spouses, signed during the marriage, that rearranges their financial rights if the marriage ends. Domestic Relations Law § 236(B)(3) authorizes agreements “made before or during the marriage” and makes them enforceable in any divorce or separation proceeding, but only if the couple follows three strict formalities and can show the deal was fair when made.1New York State Senate. New York Domestic Relations Law 236 – Special Controlling Provisions; Prior Actions or Proceedings; New Actions or Proceedings Because spouses already owe each other fiduciary duties by the time they sit down to negotiate, courts hold these agreements to a higher standard than an ordinary contract.
The Three Statutory Requirements
DRL § 236(B)(3) sets out three non-negotiable formalities. The agreement must be in writing, signed by both spouses, and acknowledged (or proven) in the same way a deed must be acknowledged before it can be recorded with a county clerk.1New York State Senate. New York Domestic Relations Law 236 – Special Controlling Provisions; Prior Actions or Proceedings; New Actions or Proceedings Miss any one of these and the document can be thrown out entirely if a spouse challenges it later.
The statute also imposes a two-part fairness test, but only for provisions dealing with spousal maintenance. Those terms must be “fair and reasonable at the time of the making of the agreement” and “not unconscionable at the time of entry of final judgment.”1New York State Senate. New York Domestic Relations Law 236 – Special Controlling Provisions; Prior Actions or Proceedings; New Actions or Proceedings Courts in practice apply fairness scrutiny to the whole document, but that dual-time test is tied specifically to maintenance. A property division clause that seemed reasonable when signed won’t face the same “unconscionable at divorce” review that a maintenance waiver will.
Why Courts Scrutinize These Agreements Closely
Postnuptial agreements differ sharply from prenups on this point. Because spouses already owe each other fiduciary duties when they negotiate, New York courts examine postnuptial agreements more closely than ordinary contracts. As the Appellate Division put it in Hershkowitz v. Levy, “in view of the fiduciary relationship existing between spouses, [postnuptial] agreements are more closely scrutinized by the courts than ordinary contracts.”2New York State Unified Court System. Hershkowitz v Levy (2021 NY Slip Op 00299) The relationship demands “the utmost of good faith” from both sides.
In practice, judges dig into the circumstances surrounding the signing: who held the bargaining power, whether both spouses understood the terms, whether there was time pressure, and whether both had access to legal advice. An agreement that might survive a challenge as a prenup can fail as a postnup if the court finds one spouse exploited the trust inherent in the marriage.
When a Court Will Set the Agreement Aside
An agreement that looks fair on its face will generally be enforced according to its terms. Courts set them aside when a challenging spouse proves unconscionability, fraud, duress, overreaching, or other inequitable conduct.2New York State Unified Court System. Hershkowitz v Levy (2021 NY Slip Op 00299)
Unconscionability means the terms are so lopsided no reasonable person would have accepted them. For maintenance provisions, a judge evaluates this at the time of the final divorce judgment, so an agreement that was fair when signed can become unenforceable if circumstances have changed dramatically.
Fraud or concealment gives the other spouse a direct path to void the agreement. Hiding assets, understating income, or failing to disclose a significant liability all qualify. Full financial transparency is the foundation the entire contract rests on.
Duress or overreaching covers threats, coercion, or exploitation of a power imbalance. Courts look at the totality of circumstances, including the age, education, and sophistication of both parties.
New York General Obligations Law § 5-311 adds one more limit: spouses cannot contract away support obligations to the point where one would become unable to support themselves and likely to become a public charge. A maintenance waiver that crosses that line is void regardless of what the parties agreed to.
Full Financial Disclosure
No postnuptial agreement survives scrutiny without thorough financial disclosure from both spouses. The fiduciary standard demands that each side have a clear, accurate picture of the other’s financial situation before signing.
On the asset side, that means real estate deeds with current appraisals, recent bank and brokerage statements, retirement account balances, life insurance policies, and ownership interests in any business. Liabilities matter just as much: mortgages, student loans, credit card balances, and any personal guarantees on business debt. The goal is distinguishing between separate property (what each spouse brought into the marriage or received as a gift or inheritance) and marital property (what accumulated during the marriage), because those categories drive how the agreement allocates everything.
Privately held businesses need a formal appraisal by a professional, not an owner’s estimate. Skipping that step is one of the fastest ways to hand the other side an argument that the agreement was based on incomplete disclosure.
What the Agreement Can and Cannot Cover
DRL § 236(B)(3) spells out the permitted scope. Property ownership and division is the core use: spouses can designate specific assets as separate property, agree on how marital property will be split in a divorce, or reclassify property from one category to the other. Without an agreement, New York applies equitable distribution, where a judge weighs statutory factors to divide marital property. An agreement replaces that process with the couple’s own terms.1New York State Senate. New York Domestic Relations Law 236 – Special Controlling Provisions; Prior Actions or Proceedings; New Actions or Proceedings
Spousal maintenance can be fixed at a specific amount or duration, or waived entirely, subject to the fair-and-reasonable and unconscionability tests. A complete waiver is enforceable in New York as long as it doesn’t leave either spouse at risk of becoming a public charge.
Testamentary provisions and elective share waivers are also permitted. A spouse can agree to make (or not contest) certain provisions in a will, or waive the right to elect against the other’s estate. This is particularly relevant for blended families where each spouse wants to ensure assets pass to children from a prior relationship.
Child custody and child support are the hard limit. The statute permits provisions for “the custody, care, education and maintenance of any child,” but a court will independently review both issues during any separation or divorce proceeding to ensure the arrangement serves the child’s best interests.3New York City Bar. Postnuptial Agreements A provision that tries to lock in a permanent custody schedule or waive child support is not binding. Judges have independent authority over these matters and will override the agreement if circumstances warrant. Couples can express their intentions about schooling, religious upbringing, or living arrangements, but those provisions serve as a starting point for the court, not a final word.
Getting the Acknowledgment Right
The acknowledgment requirement is the step that trips up the most couples. The statute demands that the agreement be “acknowledged or proven in the manner required to entitle a deed to be recorded.”1New York State Senate. New York Domestic Relations Law 236 – Special Controlling Provisions; Prior Actions or Proceedings; New Actions or Proceedings That is more than getting the document notarized. The notary must complete a certificate of acknowledgment that substantially follows the form prescribed in Real Property Law § 309-a, confirming that the signer appeared personally and acknowledged executing the document.4New York State Senate. New York Code RPP 309-A – Uniform Forms of Certificates of Acknowledgment or Proof Within This State
A notary who simply stamps a signature without completing the full certificate creates a defective document. Courts have voided postnuptial agreements over exactly this kind of procedural failure. Each spouse should sign separately in front of the notary, receive their own certificate, and keep an original copy in a secure location. If the acknowledgment is wrong at the time of signing, the agreement is vulnerable from day one.
Separate Attorneys for Each Spouse
New York doesn’t technically require each spouse to have an independent attorney, but going without one is a serious risk. Courts scrutinize postnuptial agreements more closely when one or both spouses lacked independent representation, and are more likely to refuse enforcement if they suspect unfairness.3New York City Bar. Postnuptial Agreements The same attorney representing both spouses creates a conflict of interest that can undermine the entire agreement.
Separate counsel does two things. It ensures each spouse understands what they’re giving up, and it makes the agreement harder to attack later, because neither side can credibly claim confusion about the terms. Attorney fees for drafting vary with the complexity of the couple’s finances, but the cost of a solid agreement is small compared to the cost of litigating equitable distribution in a contested divorce.
Tax and Retirement Considerations
Reclassifying property in a postnuptial agreement can trigger federal tax questions many couples overlook. Under 26 U.S.C. § 1041, transfers of property between spouses are treated as gifts for tax purposes, so no gain or loss is recognized at the time of transfer, and the receiving spouse takes the transferor’s original tax basis.5Office of the Law Revision Counsel. 26 U.S. Code 1041 – Transfers of Property Between Spouses or Incident to Divorce That basis carryover matters: if one spouse transfers appreciated stock to the other, the recipient will owe capital gains tax on the original appreciation when they eventually sell.
Gifts between U.S. citizen spouses qualify for an unlimited marital deduction under 26 U.S.C. § 2523, so transfers under a postnuptial agreement generally don’t consume any gift tax exclusion.6Office of the Law Revision Counsel. 26 USC 2523 – Gift to Spouse7Internal Revenue Service. What’s New – Estate and Gift Tax One major exception: if the receiving spouse is not a U.S. citizen, the unlimited marital deduction does not apply, and the annual exclusion for gifts to a non-citizen spouse is capped. Couples where one spouse is a non-citizen should consult a tax advisor before finalizing any property transfers.
Retirement accounts come with a separate problem. ERISA governs most employer-sponsored plans and preempts state law, so a postnuptial agreement alone cannot force a plan administrator to redirect benefits. The plan honors its own documents and beneficiary designations unless it receives a Qualified Domestic Relations Order. A QDRO is a court order directing the plan to pay a portion of benefits to an alternate payee, and it generally arises from a divorce or legal separation proceeding. A postnuptial agreement can specify how retirement assets will be divided, but the actual transfer won’t happen until a court issues the QDRO during the divorce. The agreement should use QDRO-ready language so there’s no ambiguity when the time comes. Writing “spouse gets half the 401(k)” without addressing the QDRO process leaves a gap ERISA won’t fill.
Changing or Canceling the Agreement Later
A postnuptial agreement is not permanent. Both spouses can modify or revoke it at any time, as long as they follow the same formalities required for the original: a written amendment, signed by both parties, and properly acknowledged. Oral modifications will not hold up. Any changes should be made while the marriage is stable. Courts are more likely to question amendments made after one spouse has started thinking about separation, because the bargaining dynamics shift once divorce is on the horizon.
If both spouses want to cancel the agreement entirely, they can execute a written revocation following the same acknowledgment process. Modification requires mutual consent. One spouse cannot unilaterally change or withdraw from the agreement.