What to know:
- Prenups are legal and recognized in all 50 states and D.C., but only 29 states plus D.C. have adopted the UPAA or its successor, the UPMAA, per the Uniform Law Commission.
- In the 21 non-UPAA states, each state applies its own enforceability standard built from statutes and court decisions, so there is no single national rule.
- Roughly fourteen states apply some form of "second look" doctrine, per family-law author Linda Ravdin (ABA, 2017), meaning a court can decline to enforce a prenup that was fair when signed but has become unconscionable by divorce.
- Massachusetts is a leading example: under DeMatteo v. DeMatteo, 436 Mass. 18 (2002), a prenup must be fair when signed and conscionable when enforced.
- First builds every agreement around the enforceability rules of the couple's own state, so your prenup is written to hold up where you actually live, not to a generic national template.
You did the work of talking through a prenup with your partner. Then you started reading online, and a quiet worry crept in: is there some national standard your agreement has to meet, and what happens if your state doesn't follow it? It is a fair question, and the answer is more reassuring than the internet often makes it sound.
Marriage is common, and so is the planning around it. The National Center for Family & Marriage Research, drawing on U.S. Census Bureau American Community Survey 2024 1-year estimates, counted roughly 2.39 million marriages and 986,810 divorces in the United States in 2024. Millions of couples make these agreements every year, across every state. The rules that decide whether a prenup holds up, though, are not identical everywhere. Some states adopted a shared model law. Others wrote their own. Here is what that difference means for you.
What is the UPAA, and why does it exist?
Picture two couples who each sign a valid prenup, then one couple moves across a state line. Should their agreement suddenly mean something different in the new state? That portability problem is what the Uniform Premarital Agreement Act was built to address.
The Uniform Law Commission drafted the UPAA in 1983 to make prenup rules more consistent from state to state. A "uniform act" is a model statute a nonpartisan body writes and then offers to state legislatures, each of which can adopt it, adopt it with changes, or decline. The idea is that if enough states enact the same framework, an agreement valid in one is more likely to be honored in another. A later version, the Uniform Premarital and Marital Agreements Act (UPMAA), updated the model in 2012. Cornell's Legal Information Institute keeps a plain-language overview of what a premarital agreement is if you want the basic definition.
The UPAA sets out core requirements most people would recognize as fair: the agreement must be in writing, signed voluntarily, and backed by reasonable disclosure of each partner's finances. That baseline is the reference point everything else in this post measures against.
Which states have not adopted the UPAA?
Twenty-nine states plus the District of Columbia have adopted the UPAA or its successor UPMAA, according to the Uniform Law Commission. The remaining 21 states apply their own enforceability rules, built from their own statutes and their own court decisions.
You will see other numbers floating around online. Some older articles say "28 states" or "about half." Those counts predate later adoptions. The current figure from the Uniform Law Commission's enactment record is 29 states plus D.C., and that is the number to trust. If you want the fuller picture of how individual states line up, our state-by-state guide to how prenuptial agreements vary across America walks through the landscape in more detail.
Rather than reciting all 21 non-UPAA states by name, the useful thing to understand is what they have in common: each one decides prenup enforceability on its own terms. That is less alarming than it sounds, which is where we go next.
Are prenups still enforceable in states without the UPAA?
Yes. Prenuptial agreements are recognized in all 50 states and the District of Columbia. Whether a state adopted the UPAA affects the standard a court applies, not whether prenups are allowed at all. A non-UPAA state is a state with its own rulebook, not a state where prenups fail.
In practice, those rulebooks tend to test the same fundamentals: Was the agreement in writing? Did both partners sign it voluntarily? Did each partner disclose their finances honestly? Was the result fair? Our explainer on what makes a prenup enforceable covers those common requirements, and they hold up as good practice no matter which column your state sits in.
New York is a useful non-UPAA example. Under New York Domestic Relations Law § 236(B)(3), a prenup is enforceable when it is in writing, signed by both parties, and acknowledged with the same formality required to record a deed. That acknowledgment requirement is stricter than the bare UPAA baseline, and it shows the pattern clearly: several non-UPAA states demand more, not less. Understanding what happens if you don't have a prenup is part of why getting the enforceability details right matters in the first place.
Here is how the two groups compare at a glance.
| Dimension | UPAA/UPMAA states | Non-UPAA states |
|---|---|---|
| Governing framework | UPAA/UPMAA model statute, with state variations | State-specific statutes and case law |
| Number of jurisdictions | 29 states plus D.C. | 21 states |
| Fairness timing | Primarily judged at execution | Often re-examined at enforcement in "second look" states |
| Predictability across state lines | Designed for portability | Depends on the destination state's own rules |
| What stays the same | Writing, voluntariness, and disclosure matter | Writing, voluntariness, and disclosure matter |
What is the "second look" test, and where does it apply?
Most people assume a prenup is judged only by what was true on the day it was signed. In many states that is right. In others, a court can take a second look.
The "second look" doctrine lets a court re-examine a prenup's fairness at the time of divorce, not only when it was signed. Under it, a court can decline to enforce an agreement that was fair when the couple signed it but has become unconscionable (so one-sided or unfair that enforcing it would be unjust) by the time the marriage ends. Roughly fourteen states apply some form of this doctrine, according to family-law author Linda J. Ravdin in her 2017 analysis for the ABA Family Law Section. Ravdin's work also makes a broader point worth sitting with: adopting the UPAA did not create true uniformity, because states that enacted it often added their own wrinkles.
The practical meaning of a second-look rule is that a prenup which was reasonable at signing can still be scrutinized years later if circumstances shifted dramatically. That is a reason to build one that is fair on its face and stays defensible over time, not a reason to skip a prenup.
How does Massachusetts show a stricter standard in action?
Massachusetts is the clearest illustration of a two-look framework, and it has not adopted the UPAA. Its courts apply a standard drawn from DeMatteo v. DeMatteo, 436 Mass. 18 (2002).
Under DeMatteo, a Massachusetts prenup must clear two separate checks. It must be fair and reasonable when it is signed, and it must be conscionable when it is enforced. A court looks once at the moment of signing and again at the moment of divorce. An agreement can pass the first test and still face the second. That dual standard, reinforced by Mass. Gen. Laws ch. 209, § 25, can be more demanding than the UPAA framework, which leans more heavily on fairness at execution. If you are in Massachusetts specifically, our Massachusetts prenup resource goes deeper on what couples there should know.
The lesson from Massachusetts generalizes. In a non-UPAA state, knowing your state's actual test, not a generic national one, is what lets you draft something built to hold up.
What should you do if you live in a non-UPAA state?
The reassuring part is that the fundamentals do not change from state to state. Whether or not your state adopted the UPAA, the same practices protect an agreement: full financial disclosure, a voluntary signing with real time to review, and terms that are fair to both partners. A prenup built on those foundations is designed to hold up under most state tests, UPAA or not.
What changes is the fine print, and that is where drafting to your own state's rules earns its keep. A New York couple needs the deed-level acknowledgment. A Massachusetts couple should expect a second look at enforcement. A couple in a UPAA state has a more portable baseline. If you are weighing where and how to sign, our guides on whether it matters where a prenup is signed and on jurisdiction and why it matters unpack the details.
One more scenario worth naming: moving. Couples often ask whether relocating voids a prenup. It generally does not, but a court in your new state may apply that state's own enforceability rules to your agreement. The UPAA was designed partly to smooth that transition, which is one reason strong disclosure and fair terms travel well regardless of where you first signed.
Frequently Asked Questions
Which states have not adopted the UPAA?
Twenty-nine states plus the District of Columbia have adopted the UPAA or its successor UPMAA, according to the Uniform Law Commission. The remaining 21 states have not, and instead apply their own statutes and court-made rules to decide whether a prenup is enforceable. Prenups remain valid in all of them.
Are prenups enforceable in states that didn't adopt the UPAA?
Yes. Prenuptial agreements are recognized in all 50 states and D.C. In non-UPAA states, courts evaluate a prenup under that state's own enforceability tests, which cover writing, voluntariness, disclosure, and fairness. Several of these tests are stricter than the UPAA baseline.
What is the "second look" test?
The "second look" doctrine lets a court refuse to enforce a prenup that was fair when signed but has become unconscionable by the time of divorce. Roughly fourteen states apply some version of it, per family-law author Linda Ravdin. Massachusetts is a well-known example of the approach.
Does Massachusetts follow the UPAA?
No. Massachusetts has not adopted the UPAA. Its courts apply a two-look test from DeMatteo v. DeMatteo, 436 Mass. 18 (2002): a prenup must be fair and reasonable when signed and conscionable when it is enforced. That dual standard can be more demanding than the UPAA framework.
If I move to a different state, will my prenup still work?
Often yes, but it depends. The UPAA was designed partly so an agreement valid in one state would be honored in another. If you move to a non-UPAA state, a court there may apply its own enforceability rules, so strong disclosure and fair terms matter regardless of where you signed.
How First helps
If you are trying to figure out whether your agreement will hold up where you live, that uncertainty is exactly what a good prenup process should remove. First builds each agreement around the enforceability rules of your own state, so you are not guessing whether a generic template fits your situation. No national one-size-fits-all form, no guessing which rules apply, no surprises at enforcement. When you are ready, you can start with First and work through it on your own timeline.
Methodology
These figures are drawn from the Uniform Law Commission's enactment record for the UPAA and UPMAA, current as of 2026, and from Linda J. Ravdin's 2017 ABA Family Law Section analysis for the "second look" count. National marriage and divorce figures are from the National Center for Family & Marriage Research's analysis of U.S. Census Bureau American Community Survey 2024 1-year estimates.
Sources
- Uniform Law Commission: UPAA/UPMAA adoption count of 29 states plus D.C. and the 1983 history of the model act.
- Linda J. Ravdin, "Premarital Agreements and the Uniform Acts," ABA Family Law Section (2017): the "roughly fourteen" second-look states count and the point that UPAA adoption did not achieve full uniformity.
- New York Domestic Relations Law § 236(B)(3): New York's acknowledgment and enforceability requirement as a non-UPAA example.
- U.S. Census Bureau, American Community Survey: 2024 1-year estimates underlying national marriage and divorce counts.
- Cornell Legal Information Institute: plain-language definition of a premarital agreement.
First is not a law firm. The information and tools provided by First on this site are not legal advice and not a substitute for the advice of an attorney.