Prenuptial Agreements in 2026: When They Work and When Courts Throw Them Out

Prenuptial agreements used to carry a stigma. That has largely disappeared. According to a 2025 survey by the American Academy of Matrimonial Lawyers, more than 60 percent of family law attorneys reported an increase in prenup requests over the previous five years, driven especially by millennial and Gen Z couples entering marriage with student debt, small businesses, or significant separate assets.

What a prenup can actually decide

• How separate and marital property will be classified and divided in a divorce.
• Whether spousal support will be paid, and if so, how much and for how long.
• Ownership and control of businesses, professional practices, and investments.
• Rights to specific assets acquired before the marriage.
• How debts brought into the marriage will be handled.
• Estate planning coordination, including elective share waivers.

What a prenup cannot decide

• Child custody. Courts always decide custody based on the child's best interest at the time of the divorce, not at the time of the prenup.
• Child support. Cannot be waived or capped in advance.
• Anything that violates public policy.
• Personal, non financial matters like household chores or intimacy expectations. These clauses are unenforceable and often used against the drafter.

The four pillars of an enforceable prenup

1. Voluntary execution. The agreement must be signed without coercion or duress. A prenup handed over the night before the wedding often fails this test.
2. Full and fair financial disclosure. Each party must know what the other has before signing.
3. Independent counsel. Each party should have their own attorney review the agreement. States differ on whether this is strictly required, but it is the single best insurance against later invalidation.
4. Substantive fairness. Terms that are grossly one sided, or that would leave one spouse destitute, are more vulnerable in court.

The Uniform Premarital Agreement Act

The Uniform Premarital Agreement Act or its updated version, the Uniform Premarital and Marital Agreements Act, has been adopted in some form by more than 25 states. It generally provides that a prenup is enforceable unless the challenging party proves it was involuntary or the result of unfair disclosure. Non uniform states apply their own tests, but the underlying principles are similar.

Common drafting mistakes

• Failing to attach detailed financial schedules.
• Presenting the document days before the wedding, which supports a claim of duress.
• Using boilerplate downloaded from the internet without state specific review.
• Including provisions that regulate personal conduct.
• Vague or contradictory language that gives courts room to reinterpret intent.

Postnuptial agreements as a backup

Couples who did not sign a prenup can enter a postnuptial agreement after the wedding. The requirements are similar, but courts often apply a stricter fairness standard because the parties are already married and have a fiduciary relationship. Postnups are especially common when one spouse launches a business, receives a large inheritance, or when the couple wants to formalize a reconciliation after a period of separation.