A postnuptial agreement is a contract between spouses, signed during the marriage, that sets out who owns what and how support works if the marriage ends. It is worth considering after a business sale, a promotion to partner, an inheritance, or the purchase of an apartment with one spouse's separate money. It must be in writing, signed and acknowledged like a deed (DRL § 236(B)(3)), and because spouses owe each other the utmost good faith, courts check it for fairness. Fixed fees start at $3,000.
At a glance
- Fixed fees: Standard Postnup $3,000; Complex Postnup $5,000.
- Typical triggers: a liquidity event, a partnership admission, an inheritance, buying an apartment with separate funds, or an outdated prenup.
- An unacknowledged postnup is unenforceable even if both spouses signed it (Matisoff v. Dobi).
- Full disclosure and a separate lawyer for each spouse matter even more than for a prenup.
Postnups for Manhattan couples
A postnup does for a married couple what a prenup does for an engaged one: it replaces New York's default rules on property and support with terms the two of you choose. Without an agreement, property either spouse acquires during the marriage is generally marital and is divided equitably in a divorce, regardless of whose name is on it (DRL § 236(B)(1)(c), (5)(c)). We prepare postnups for couples throughout Manhattan, with meetings by phone or video and signing at our office or before a notary near you. The general rules are on our main postnuptial agreement page.
After a sale, an IPO or a new partnership
When a company is sold, goes public or admits you as a partner, value that was hard to measure becomes cash, stock or a capital account. If the business or the equity predates the marriage, part of it may be separate property; if it was built during the marriage, it is generally marital. Equity granted during the marriage is divided under the time-based approach the Court of Appeals adopted in DeJesus v. DeJesus, 90 N.Y.2d 643 (1997). A postnup signed around the event can fix how the proceeds are characterized, whether reinvested money stays separate, and how future grants are treated. If a partnership or operating agreement asks for a spouse's consent, the postnup and that consent should be drafted to match.
Buying an apartment with separate money
Suppose one spouse uses money saved before the marriage, or an inheritance, toward a co-op or condo bought during the marriage. The apartment is presumed marital, and the spouse who used separate funds must prove the contribution to get credit for it (Fields v. Fields, 15 N.Y.3d 158 (2010)). Titling the apartment in both names can make that harder. A postnup signed before the closing can preserve a credit for the separate contribution, set each spouse's share, and say what happens if the apartment is sold. For a co-op, the shares and proprietary lease should be titled consistently with the agreement.
An inheritance or trust distribution
An inheritance is separate property (DRL § 236(B)(1)(d)(1)), but once it is deposited in a joint account, used for family expenses or invested with marital money, tracing it becomes difficult. A postnup can identify the inheritance, say that income and growth stay separate, and allow it to be invested together without losing its status. See trusts and equitable distribution.
Updating or replacing a prenup
A prenup signed years ago may not fit a marriage with children, a move or very different incomes. A postnup can update maintenance terms, estate provisions and any halachic provisions, or replace the prenup entirely. It must meet the same requirements: in writing, signed by both spouses and acknowledged. If maintenance is limited or waived, include the guideline calculation; a 2025 Kings County trial court refused to enforce a maintenance waiver, signed by a spouse without a lawyer, that did not state the parties' incomes or the guideline amount (J.M. v. G.V., 87 Misc. 3d 171 (Sup. Ct. Kings County 2025)).
Why fairness matters more after the wedding
Engaged couples bargain at arm's length; spouses do not. "Agreements between spouses, unlike ordinary business contracts, involve a fiduciary relationship requiring the utmost of good faith" (Christian v. Christian, 42 N.Y.2d 63, 72 (1977)). In Petracca v. Petracca, 101 A.D.3d 695 (2d Dep't 2012), the Second Department upheld an order setting aside a postnup as manifestly unfair where the wife had given up substantial property and inheritance rights. To reduce that risk:
- exchange full, documented financial disclosure and attach it;
- have a separate lawyer for each spouse;
- allow time to review, without a deadline attached; and
- keep terms that each of you can explain, especially on maintenance, which must be fair when signed and not unconscionable at judgment (DRL § 236(B)(3)).
What a postnup cannot do
A postnup does not bind creditors. It cannot override the court on child support or custody (DRL § 240), and under General Obligations Law § 5-311 it cannot leave a spouse likely to become a public charge or require the spouses to divorce.
Fixed fees
Standard Postnup
$3,000
Basic asset protection
Complex Postnup
$5,000
Business or significant assets
Each fee includes a review of the marital assets, customized terms, a confidential process and properly executed documentation. Start online or call (718) 975-1123.