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Postnuptial Agreement

A contract between spouses, signed during the marriage, that decides how property and support would be handled on divorce or death, and why courts scrutinize it more closely than a prenup.

Informational only - this is not legal advice. These definitions explain general legal vocabulary in plain English. They are not advice about your situation, reading them creates no attorney-client relationship, and the law differs from state to state and changes over time. For advice you can rely on, speak to a lawyer licensed in your state.

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What it means

A postnuptial agreement is a written contract between spouses, made after the wedding, that sets out how property will be divided and whether spousal support will be paid if the marriage ends in divorce, and often what each spouse receives at the other's death. Couples sign them after one spouse inherits or starts a business, when one leaves work to care for children, when they move to a state with different property rules, or as part of a reconciliation. It does the same job as a prenuptial agreement, but it is made between people who are already married.

That difference is why courts look harder at postnups. Spouses owe each other duties of good faith and fair dealing, and in some states a full fiduciary duty, so an agreement in which one spouse gives up rights is examined for fairness in a way an agreement between engaged people may not be. Requirements vary by state, but courts commonly ask whether the agreement is in writing and signed by both spouses, whether each made full and fair disclosure of their assets, debts and income, whether each signed voluntarily and not under pressure or a threat of divorce, whether each had the chance to get independent legal advice, and whether the terms were fair when signed and are not unconscionable when enforced. A few states have adopted a uniform act that applies the same rules to premarital and marital agreements; elsewhere case law governs.

Some things a postnup cannot settle. Agreements about child support and custody do not bind a court, which decides those by the child's best interests at the time. Waiving a spouse's survivor rights in an employer retirement plan requires the spouse's written, witnessed consent in the form federal law prescribes, which a general property agreement may not satisfy. And an agreement that would leave a spouse dependent on public assistance may not be enforced as to support. See also marital property division.

Where this comes from

Uniform Premarital and Marital Agreements Act (Uniform Law Commission, 2012), §§ 9 (enforcement: duress, independent counsel, disclosure, unconscionability), 10 (unenforceable terms, including child support and custody). Fiduciary duty between spouses, for example Cal. Fam. Code § 721(b). Enforceability standards for marital agreements: Ansin v. Craven-Ansin, 457 Mass. 283 (2010). Spousal consent to waive survivor benefits in a retirement plan: ERISA § 205(c)(2), 29 U.S.C. § 1055(c)(2); Internal Revenue Code § 417(a)(2), 26 U.S.C. § 417(a)(2). Marital agreements are otherwise governed by each state's statutes and case law.

When people hire a lawyer for this

Each spouse should have their own family law lawyer; an agreement signed when only one spouse had advice is the one most likely to be thrown out later. Exchange complete financial disclosure in writing, including business interests, retirement accounts and expected inheritances, and allow time between the draft and the signing. If the agreement is part of a reconciliation after a separation, or if one spouse is far more dependent on the other, expect the court to look especially closely at fairness.

Worried about the cost? A lawyer can be hired for one part of a case only (limited-scope representation), may be paid from what a claim recovers (contingency fee), or may be free through a pro bono program or legal aid; a court can also waive its own filing fees.

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Related terms

Entries on the same subject:

Other entries in the same area of law, each written from the same primary sources.

AdoptionThe court order that makes a child legally the son or daughter of someone other than the birth parents - the kinds of adoption, whose consent is required, how the birth parents' rights end, the home study and the hearing, and what the order changes about inheritance, records and the child's name.
Child SupportMoney one parent pays the other toward a child's living costs, set in most cases by a state formula rather than by negotiation.
Child Support EnforcementHow unpaid child support is collected - income withholding, tax refund intercepts, license and passport sanctions, liens and contempt - and the free help available from state child support agencies.
Cohabitation Agreement (Unmarried Couples)Why unmarried partners who live together have few of the property and support rights spouses have, what a written cohabitation agreement can cover, and what courts do without one.
Collaborative Divorce (Collaborative Law)A way to settle a divorce out of court in which both spouses and their lawyers agree in writing to negotiate, and the lawyers must withdraw if the case goes to court.
Common-Law MarriageA marriage formed without a license or ceremony by living together as spouses and holding yourselves out as married - which states still allow it, what has to be proved, why every state recognizes one validly formed elsewhere, and what it means for property, support and inheritance when the relationship ends.
Divorce MediationA process in which a neutral mediator helps separating spouses negotiate their own agreement on property, support and parenting, instead of having a judge decide for them.
Establishing PaternityThe legal step that makes a man a child's father in law - and signing the hospital form is one of two routes, not a formality.
Grandparent and Third-Party VisitationWhen a court can order that a child spend time with a grandparent, step-parent or other non-parent over a parent's objection - the constitutional limit set by the Supreme Court, the circumstances in which state statutes allow a petition, the special weight a fit parent's decision receives, and what a petitioner must prove.
Guardian ad Litem and Custody EvaluatorThe two neutrals a court most often appoints in a contested custody case - what a guardian ad litem does and does not do, how it differs from a child's attorney and from a custody evaluator, who pays, what they may see, and how their reports are used at trial.
Guardianship of a MinorA court order giving an adult who is not the parent legal authority over a child's care, or over the child's property, without ending the parents' rights - how it differs from custody and adoption, who can be appointed, what the parents keep, and how it ends.
Legal and Physical CustodyTwo different things the word "custody" covers: who makes major decisions for a child, and where the child lives.
Military DivorceA divorce in which one spouse is a service member, which adds federal rules on where the case can be filed, how military retired pay is divided, and what the civilian spouse keeps after the divorce.
Modifying a Custody or Support OrderChanging an existing family court order - which usually requires proving something has changed, and never happens by the parents' agreement alone.
Parenting Plan and VisitationThe written schedule and decision-making rules for a child after separation - and the document courts increasingly require rather than invite.
Prenuptial AgreementA contract made before marriage about property and support - enforceable in every state, and set aside more often than most people expect.
Protective Order (Restraining Order)A court order telling one person to stop contacting or coming near another - enforceable by police, and valid across state lines.
Relocating With a ChildMoving a child away from the other parent - the family law dispute most likely to require the court's permission before the move, not after.
Same-Sex Marriage and Family LawHow marriage, divorce, parentage and adoption law applies to same-sex couples after Obergefell, and the places where the rules still differ in practice.
Termination of Parental RightsThe court order that permanently ends the legal relationship between a parent and child - the grounds a state must prove, the heightened standard of proof and right to counsel, the difference between voluntary relinquishment and an involuntary petition, and what the order does and does not end.

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Part of the LawyerLand plain-English legal glossary. Definitions are written from primary sources - statutes and court rules - and each entry states the authority it rests on, or says plainly when the doctrine is state law with no national rule.

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