Prenuptial Agreements and Estate Planning in New York

A prenuptial agreement is not only a document about what happens if the marriage ends. In New York, it is also one of the most powerful tools for shaping what happens when one spouse dies. A valid prenup can fundamentally alter the spousal protections built into New York estate and inheritance law. For Westchester County families, especially those blending families, remarrying, or entering a marriage with substantial separate property, understanding how prenuptial agreements interact with estate planning is not optional. It is essential.

This guide explains how prenuptial agreements affect your estate plan, what happens to the surviving spouse’s rights when a prenup is in place, and how to coordinate a prenup with wills, trusts, and beneficiary designations.

What the Elective Share Is, and Why It Matters

New York law provides the surviving spouse with the right of election against the will. This is called the elective share, and it is one of the most important protections in estate law.

Under EPTL 5-1.1-A, the surviving spouse of a decedent who dies with a will has the right to renounce the will and take, instead, a share of the estate determined by the laws of intestacy. In most cases, this means the surviving spouse is entitled to one-third of the decedent’s net estate or $50,000, whichever is greater.

This right exists independent of what the will says. A spouse cannot be disinherited in New York. Even if a will leaves everything to a child or a charity, the surviving spouse can elect to take one-third instead.

The elective share applies only if the decedent dies with a valid will. If there is no will, New York’s intestacy laws apply, and the surviving spouse’s share depends on whether the decedent left children. With children, the surviving spouse receives one-third. Without children, the surviving spouse receives the entire estate.

For many families, this protection is essential. For others, particularly those in second marriages or with children from prior relationships, it creates tension with the estate plan. This is where prenuptial agreements enter the picture. See the elective share article for detailed information about this New York protection.

How a Prenuptial Agreement Can Waive the Elective Share

Under New York Domestic Relations Law § 236(B)(3), a prenuptial agreement is enforceable and can waive most or all of the surviving spouse’s rights to the decedent’s estate, including:

• The elective share (one-third of the net estate)
• The intestate share
• Rights to exempt property
• The right to family allowance
• Rights under the homestead exemption

This means that through a valid prenuptial agreement, a spouse can agree in advance to accept whatever the other spouse provides in the will or trust, or nothing at all.

A prenup that waives the elective share is particularly common in second marriages. A husband with adult children from his first marriage may want to ensure that his substantial estate passes to his children, not to a surviving spouse he married later in life. A prenup allows him to provide for his second spouse through life insurance, a trust, or direct gifts while directing the bulk of his estate to his children.

Similarly, a spouse who enters a marriage with significant separate property, a family business, or inherited assets may use a prenup to protect those assets from a spousal claim at death.

Requirements for a Valid Prenuptial Agreement in New York

Not every agreement is enforceable. New York has strict requirements.

In writing. The agreement must be written. Oral prenups have no legal effect.

Signed by both parties. Each spouse must sign the agreement. Signature by an attorney or agent is not sufficient.

Acknowledged before a notary. Under EPTL 5-1.1-A(f), the agreement must be acknowledged before a notary public or acknowledged and subscribed to before a justice of the Supreme Court. This acknowledgment is required for the waiver of estate rights to be valid. A simple signature is not enough; the acknowledgment is mandatory.

Fair and reasonable disclosure. Each party must make a full and fair disclosure of their assets and liabilities, or must explicitly waive the right to disclosure. The court will not enforce an agreement if one spouse made false statements about assets or deliberately concealed property. The waiver of disclosure must be knowing and voluntary.

Not unconscionable. The agreement cannot be so one-sided, at the time of execution, that enforcement would be unconscionable. However, New York courts are generally deferential to prenups negotiated between parties with independent counsel. If both parties had the opportunity to consult an attorney and agreed voluntarily, the court is unlikely to set the agreement aside on unconscionability grounds.

Separate counsel is advisable. While not a legal requirement, New York courts are far more likely to enforce an agreement if each party had independent legal representation. If one party signed without an attorney, or after having only a few days to review the agreement, the court may scrutinize the agreement more carefully. Courts also disfavor prenups negotiated under time pressure, such as those signed days before the wedding.

How a Valid Prenuptial Agreement Changes the Estate Plan

Once a prenuptial agreement waiving estate rights is in place, the estate plan must be coordinated carefully with the prenup. The interaction between the two documents is critical.

The surviving spouse no longer has an automatic claim. Without a prenup, a surviving spouse can always elect to take one-third of the estate, regardless of what the will provides. With a prenup waiving the elective share, the surviving spouse’s claim is limited to whatever the will or trust actually provides. If the will leaves the surviving spouse nothing, the spouse receives nothing because the prenup precludes the elective share.

The will or trust must clearly express the parties’ intent. Many couples who execute a prenuptial agreement still intend to provide for the surviving spouse, just in a defined and limited way. The will or trust should make clear what the surviving spouse will receive: a specific dollar amount, a life estate in the home, income from a trust, or something else. The document should spell this out. Ambiguity creates room for a later dispute.

Credit shelter trust planning may change. For married couples, the absence of New York portability makes credit shelter trust planning common. However, in a second marriage with a prenup, the dynamic shifts. If the surviving spouse has waived the elective share, there is no need to structure the first spouse’s estate to provide significant benefits to the surviving spouse. Instead, the entire credit shelter trust can be structured entirely for the benefit of children or other beneficiaries. The surviving spouse’s financial security depends wholly on the prenup’s provision, or the separate property the surviving spouse brought into the marriage.

Beneficiary designations must align. Life insurance, retirement accounts, and other assets with named beneficiaries pass outside the will. These designations must be consistent with the overall estate plan and prenup. If a prenup contemplates that the surviving spouse will receive a certain amount, but life insurance and retirement accounts are left entirely to children, the provisions conflict. The named beneficiary designation will control because it passes by contract, not by will. However, the conflict signals that the documents need to be reviewed and aligned.

The Importance of Coordination in a Prenuptial Context

Coordination between the prenuptial agreement, the will, the revocable trust, and beneficiary designations is essential in all marriages. In a prenuptial context, coordination becomes critical.

Consider a common scenario: a 62-year-old man with two adult children from his first marriage remarries a woman of similar age. He has a substantial estate and wants to ensure that his children ultimately receive the bulk of his property. He and his bride execute a prenuptial agreement in which she waives her elective share. In his will, he leaves his wife $250,000 outright and the remainder of his estate to his children.

This plan makes sense if all the documents are aligned. But what if his revocable trust, drafted years earlier and never updated, still names his ex-wife as a contingent beneficiary? Or what if his IRA, which is worth more than his probate estate, names his children as beneficiaries, contradicting the prenup’s assumption that his wife will be cared for by the $250,000 bequest? Or what if his homeowner’s insurance policy, a valuable asset, is payable to his wife?

These inconsistencies do not invalidate the prenup. But they create confusion, potential disputes, and the risk that the actual distribution of assets will not reflect what the couple intended.

Coordination requires that the attorney preparing the will or trust review the prenuptial agreement, understand what the couple intends, and ensure that all documents (will, revocable trust, life insurance, retirement beneficiary designations, and any powers of attorney) reflect the same plan.

Postnuptial Agreements

A postnuptial agreement is an agreement entered into after marriage that waives or modifies a spouse’s estate rights. New York recognizes postnuptial agreements, but they are subject to much greater judicial scrutiny than prenups.

Courts view postnuptial agreements with suspicion because they are negotiated after the marital relationship has already begun. There is a presumption that the negotiating spouse, typically the spouse proposing the waiver, had greater bargaining power or influence over the other.

For a postnuptial agreement to be enforceable, the requirements are more stringent. Each party must have had independent counsel. Full disclosure of assets is typically mandatory. The agreement cannot be unconscionable, and the court will examine the circumstances under which it was negotiated. Was there time pressure? Did one spouse threaten divorce to force agreement? Did one spouse conceal assets?

Despite these hurdles, postnuptial agreements are enforceable in New York. They are often used when circumstances change after marriage, for example, when one spouse comes into an unexpected inheritance or when a blended family situation requires clarification of spousal rights.

Tax Implications

A prenuptial agreement that waives a spouse’s estate rights has important tax consequences.

The marital deduction. Under federal tax law, a decedent can pass an unlimited amount of property to a surviving spouse without incurring federal estate tax, provided that the property passes in a form that gives the surviving spouse sufficient control or benefit. This is the marital deduction, and it is one of the most valuable tax benefits in estate planning.

However, the marital deduction applies only to property that the surviving spouse actually receives. If a prenuptial agreement waives the surviving spouse’s rights, and the decedent’s will leaves property to someone else, the marital deduction is not available for that property. The deceased spouse’s estate bears the full federal estate tax burden.

This has important planning implications. A decedent with a large taxable estate might need to use the marital deduction to shelter property from federal tax. A prenup that prevents the marital deduction from being used effectively can increase the estate tax liability.

Conversely, if the couple’s combined assets exceed the federal estate tax exemption (currently $15,000,000 per person in 2026), and the plan is to shelter the maximum amount in the decedent’s credit shelter trust, a prenup that waives the surviving spouse’s rights can actually be beneficial for tax planning. The surviving spouse does not need to be a beneficiary of the marital trust; all assets can pass to the credit shelter trust for the benefit of the children.

New York estate tax. The New York estate tax implications are similar. A prenup that waives spousal rights changes which spouse bears the tax burden and how much the New York exclusion can shelter.

These tax issues are complex and require careful planning. Any couple considering a prenuptial agreement should consult with an estate planning attorney and, if the estate is large, a tax advisor.

Common Scenarios in Westchester County

Several situations commonly lead Westchester families to coordinate prenuptial agreements with estate planning.

Second marriages with adult children. This is the most common scenario. A widow or widower with adult children remarries. The new spouse may have his or her own children. Without a prenup, the spouse’s elective share would consume a significant portion of the estate that the original spouse hoped to pass to his or her children. A prenup clarifies that the surviving spouse will receive a defined amount (perhaps life insurance, a specific bequest, or income from a trust) and the remainder passes to the children.

High-net-worth marriages with separate property. One or both spouses enter the marriage with substantial separate property, inherited wealth, a family business, or real estate. A prenup protects these assets from a spousal claim at death and ensures they ultimately pass to the spouse’s family of origin or children from prior relationships.

Blended families with unequal asset distribution. In some families, one spouse has significantly more wealth than the other. A prenup can protect the wealthier spouse’s assets for his or her children while still providing for the other spouse during the marriage.

Family real estate. Some Westchester families have owned a piece of valuable real property for generations: a home in Scarsdale or Chappaqua, a vacation property, or a piece of farmland in the county. A prenup can protect that family property from becoming a contested asset if a marriage ends or when one spouse dies.

Drafting Considerations

If you are considering a prenuptial agreement, several things will improve the likelihood of enforceability and reduce the risk of later disputes:

Consult an attorney early. Do not wait until days before the wedding. Ideally, each party should consult an independent attorney weeks or months before the wedding. Time pressure is a major red flag for enforceability.

Make full disclosure. Prepare a complete financial statement listing all assets, liabilities, income, and debts. Exchange these statements before the agreement is finalized. A full disclosure, signed under penalty of perjury, is the best defense against later claims that one party concealed assets.

Acknowledge the agreement before a notary. Do not skip this step. Acknowledge the agreement before a notary public, with both parties present, and keep the notarized copy. This acknowledgment is a statutory requirement for the waiver of estate rights.

Be clear about what is waived. Specify in the agreement what rights are waived. Are you waiving the elective share only, or also the right to family allowance, homestead exemption, and other statutory rights? The clearer the language, the more difficult it is to argue later that a waiver was ambiguous or invalid.

Coordinate with the estate plan. Once the prenup is executed, immediately update the will, revocable trust, and beneficiary designations to be consistent with the prenup. Do not assume that old estate planning documents remain valid or appropriate after a prenup is signed.

When to Revisit the Agreement

Prenuptial agreements are generally permanent. However, they can be modified or revoked if both parties agree in writing. Additionally, some agreements include sunset provisions that specify the agreement’s validity period.

A couple should consider whether the prenup remains appropriate as circumstances change. If a second marriage has been stable for many years, the reasons for the prenup may have diminished. The couple may want to amend the agreement to provide greater benefits to the surviving spouse. Conversely, if the reason for the prenup, which is protection of assets for children from a prior relationship, remains important, the agreement should be left in place.

These are personal decisions that depend on the couple’s circumstances and intentions. An attorney can help explain the implications of modifying or revoking a prenup.

Planning Next Steps

If you are entering a marriage and considering a prenuptial agreement, or if you are recently married with a prenup in place, take these steps:

Consult with an estate planning attorney. Explain your family situation, your intentions, and any existing prenuptial agreement. The attorney should review the prenup and advise how it affects your estate plan.

Prepare a complete financial inventory. List all assets, liabilities, and income. Knowing your total estate value is essential for coordinating the prenup with the estate plan.

Review beneficiary designations. Check life insurance policies, retirement accounts (IRA, 401(k), 403(b)), and any other assets with named beneficiaries. Ensure these align with your prenup and your overall estate plan.

Draft or update your will and revocable trust. These documents should reflect what you intend to provide to your spouse under the prenup, and what you intend to pass to your children or other beneficiaries.

Coordinate all documents. Your attorney should ensure that the prenup, will, trust, and beneficiary designations all work together and reflect your intentions.

Prenuptial agreements and estate planning are deeply intertwined, particularly in the blended family and second-marriage contexts common in Westchester County. Careful planning and thoughtful coordination of all documents can protect your family interests, provide security for your spouse, minimize disputes after your death, and help ensure your legacy passes as you intend.

Consultation with an Attorney

Prenuptial agreements and the coordination of estate planning are complex matters that require individualized legal advice. The tax implications are substantial, and the enforceability of a prenup depends on the specific facts and circumstances of your situation. If you are considering a prenuptial agreement, or if you have an existing prenup and need to coordinate your estate plan, consult with an experienced New York estate planning attorney. This is not an area for generic templates or do-it-yourself solutions.