A prenup can be thrown out in Massachusetts when it fails the two-stage DeMatteo test: it must be fair and reasonable at signing (the "first look") and conscionable at enforcement (the "second look"). Common grounds include nondisclosure of assets, lack of independent counsel, coercion, or terms that strip a spouse of substantially all marital rights under Mass. Gen. Laws ch. 209 § 25.
Massachusetts enforces most prenuptial agreements, but courts retain unusual power to invalidate them at divorce. Unlike many states, Massachusetts applies a "second look" at the time of enforcement, meaning an agreement valid when signed in 2010 could still be set aside in 2026 if changed circumstances make enforcement unconscionable. This guide explains exactly when and how a prenup can be thrown out in Massachusetts, the precise legal standards courts apply, and what evidence challenges succeed or fail.
Key Facts: Massachusetts Divorce and Prenup Enforcement
| Factor | Massachusetts Standard |
|---|---|
| Filing Fee | $215 Complaint + $15 summons = $230 minimum (some courts add $90 = $305). As of March 2026. Verify with your local clerk. |
| Waiting Period | 120 days after judgment of divorce nisi for a contested (1B) divorce; 90 days for a joint (1A) petition |
| Residency Requirement | 1 year of continuous residence, OR domicile at filing if grounds arose in Massachusetts (M.G.L. c. 208 § 5) |
| Grounds | No-fault (irretrievable breakdown) and seven fault grounds under M.G.L. c. 208 § 1 |
| Property Division Type | Equitable distribution (M.G.L. c. 208 § 34) |
| Prenup Statute | Mass. Gen. Laws ch. 209 § 25 |
| Governing Case | DeMatteo v. DeMatteo, 436 Mass. 18 (2002) |
Can a Prenup Be Thrown Out in Massachusetts?
Yes, a prenup can be thrown out in Massachusetts, but the burden is high and falls on the party challenging it. Massachusetts courts apply the two-look test from DeMatteo v. DeMatteo, 436 Mass. 18 (2002): the agreement must be (1) fair and reasonable when signed and (2) conscionable when enforced. An agreement fails the first look only if its terms "essentially vitiate the very status of marriage," a deliberately demanding standard.
Massachusetts authorizes prenuptial agreements by statute under Mass. Gen. Laws ch. 209 § 25, titled "Antenuptial settlements; force and effect." The statute gives these agreements substantial weight, providing that property limitations "shall take effect at the time of the marriage in like manner as if they had been contained in a deed conveying the property limited." In practice, a properly executed Massachusetts prenup carries the same legal force as a property deed. Because of this strong statutory foundation, courts begin with a presumption that a validly signed agreement should be enforced. A challenger must produce specific evidence of procedural defect at signing or genuine unconscionability at enforcement to get a prenup thrown out in Massachusetts.
The First Look: Was the Prenup Fair and Reasonable When Signed?
The first look examines fairness at execution, and a Massachusetts prenup survives unless its terms "essentially vitiate the very status of marriage." Courts weigh four procedural factors: whether each party had independent counsel, whether there was adequate time to review the agreement, whether both parties understood the terms and their effect, and whether each understood the marital rights being waived. Full financial disclosure is central to this analysis.
The Supreme Judicial Court set an intentionally high bar at the first look. An agreement is presumptively valid even when its terms appear lopsided, provided the challenging spouse signed knowingly and voluntarily with adequate disclosure. In DeMatteo itself, the SJC upheld an agreement that left the wife with less than 1/200 of the couple's assets after a 10-year marriage that produced two children, because she was fully informed of her husband's finances at signing and was left with fair and reasonable means to support herself. The lesson is clear: mere financial imbalance does not invalidate a Massachusetts prenup. To win a first-look challenge, a spouse must show a procedural defect, such as hidden assets, no opportunity to consult counsel, last-minute pressure on the eve of the wedding, or terms so extreme they leave the spouse destitute. These procedural failures are what get a prenup thrown out in Massachusetts at the first stage.
The Second Look: Is the Prenup Conscionable at Divorce?
The second look is Massachusetts's distinctive feature: even a validly signed prenup can be set aside if enforcement at divorce would be unconscionable. The standard is conscionability, not mere fairness. A court will refuse enforcement only when changed circumstances during the marriage would leave the contesting spouse "without enough property, maintenance, or appropriate employment to support herself or himself."
The purpose of the second look, the SJC explained, is to ensure the agreement "has the same vitality at the time of the divorce that the parties intended at the time of its execution." Qualifying changed circumstances are significant and unanticipated, such as a spouse who develops a disabling illness, a long-term homemaker who sacrificed career earning capacity, or severe inflation that devalued agreed support. Importantly, the unconscionability threshold is high. An agreement will not be thrown out merely because it now seems unfair or because one spouse will enjoy a far higher standard of living. The agreement must leave one party essentially destitute, or nearly so, while the other flourishes. There is also a public-policy ceiling: under DeMatteo at 37, if a court finds the agreement strips a spouse of substantially all marital rights and interests, enforcement is contrary to public policy and the prenup is unenforceable. Massachusetts courts have used the second look to invalidate agreements, including two prenuptial agreements the Appeals Court refused to enforce in 2015.
Grounds That Get a Prenup Thrown Out in Massachusetts
The most successful challenges to a Massachusetts prenup involve nondisclosure, lack of independent counsel, coercion, or unconscionable terms at enforcement. Courts evaluate both the circumstances at signing and the practical effect at divorce. A challenge backed by documentary evidence of one of these defects has a meaningful chance of succeeding under the DeMatteo framework codified against Mass. Gen. Laws ch. 209 § 25.
The following grounds form the core of an invalid prenup challenge in Massachusetts:
- Inadequate financial disclosure: One party concealed or understated assets, income, or debts before signing. Full and fair disclosure is a foundational requirement.
- No independent legal counsel: A spouse signed without the opportunity to consult an attorney, particularly when the agreement was drafted by the wealthier spouse's lawyer.
- Insufficient review time: The agreement was presented days or hours before the wedding, leaving no realistic chance to negotiate or seek advice.
- Duress or coercion: One party was pressured, threatened, or given an ultimatum, such as "sign or the wedding is off."
- Fraud or misrepresentation: A party lied about material facts to induce the other to sign.
- Lack of understanding: A spouse did not understand the terms or the marital rights being waived, sometimes due to a language barrier.
- Unconscionable at enforcement: Changed circumstances during the marriage would leave the contesting spouse unable to support themselves.
- Terms vitiating marriage: Provisions that strip substantially all marital rights, violating public policy under DeMatteo.
How Prenups and Postnuptial Agreements Differ in Massachusetts
Massachusetts applies a more demanding standard to postnuptial agreements than to prenups. The governing case for postnups is Ansin v. Craven-Ansin, 457 Mass. 283 (2010), where the SJC held that marital agreements made during marriage are not per se against public policy but must satisfy five specific factors. Because spouses owe each other the highest duty of good faith and fair dealing, the disclosure standard for a postnup is "rigorous."
The distinction matters because the two types of agreement face different scrutiny when challenged. A prenup is judged under the DeMatteo two-look test, while a postnup must clear the five-factor Ansin test, which pays particular attention to the dynamics of an existing marriage. This table summarizes the key differences:
| Feature | Prenuptial Agreement | Postnuptial Agreement |
|---|---|---|
| Governing case | DeMatteo v. DeMatteo, 436 Mass. 18 (2002) | Ansin v. Craven-Ansin, 457 Mass. 283 (2010) |
| When signed | Before marriage | During marriage |
| Statute | M.G.L. c. 209 § 25 | Recognized by case law (Ansin) |
| Test | Two-look (fair/reasonable at signing; conscionable at enforcement) | Five-factor test |
| Disclosure standard | Full and fair | Rigorous (heightened) |
| Scrutiny level | High | Higher |
Under the five-factor Ansin standard, a Massachusetts postnup is enforceable only if: each party had an opportunity to obtain separate counsel; there was no fraud or coercion; all assets were fully and fairly disclosed; each party knowingly and explicitly waived marital rights; and the terms were fair and reasonable both at signing and at enforcement. The heightened disclosure rule reflects that postnups lack the procedural safeguards of divorce proceedings, where sworn financial statements and discovery are required.
What Happens If a Prenup Is Thrown Out in Massachusetts
If a prenup is thrown out in Massachusetts, the court divides property under the equitable distribution statute, M.G.L. c. 208 § 34, as if no agreement existed. Equitable distribution does not mean a 50/50 split; it means a fair division based on statutory factors. The judge considers the length of the marriage, each spouse's contribution, conduct, age, health, occupation, and future earning capacity.
When an invalid prenup is set aside, the financial outcome can shift dramatically because the protected separate property the agreement carved out may become subject to division. Under M.G.L. c. 208 § 34, Massachusetts judges have broad discretion to assign to either spouse all or part of the estate of the other, including property acquired before the marriage and inherited or gifted assets. This is why challenging an unconscionable prenup in Massachusetts can be worth substantial sums. The court may also reconsider alimony, which a prenup often waives or caps. Massachusetts alimony is governed by the Alimony Reform Act and is calculated based on need and the length of the marriage. A spouse who successfully gets a prenup thrown out may recover alimony rights the agreement attempted to eliminate, subject to the durational and amount limits set by Massachusetts law.
Practical Steps to Challenge a Prenup in Massachusetts
To challenge a prenup in Massachusetts, the contesting spouse files the issue within the divorce action in the Probate and Family Court and presents evidence of a procedural defect or unconscionability. The base filing fee for a Complaint for Divorce is $215 plus a $15 summons, totaling $230 (some divisions add a $90 surcharge, reaching $305). As of March 2026, verify current fees with your local clerk.
A successful challenge requires building an evidentiary record, not simply arguing the agreement feels unfair. The following steps strengthen a challenge to an invalid prenup:
- Gather signing-date evidence: Collect emails, drafts, and timelines showing when the agreement was presented and how much time was allowed for review.
- Document disclosure failures: Compile financial records proving assets, income, or debts that were hidden or understated before signing.
- Prove the counsel gap: Show whether you had access to independent legal advice or were steered to the other spouse's attorney.
- Establish coercion: Preserve evidence of ultimatums, threats, or pressure near the wedding date.
- Demonstrate changed circumstances: For a second-look challenge, document health changes, lost earning capacity, or other shifts since signing that make enforcement unconscionable.
- Retain a Massachusetts family law attorney: Prenup enforceability litigation under DeMatteo is fact-intensive and requires experienced counsel.
Massachusetts residency rules apply to the underlying divorce. Under M.G.L. c. 208 § 5, you must have lived in the Commonwealth continuously for one year before filing, unless the grounds for divorce arose in Massachusetts and you are domiciled here at filing. Venue under M.G.L. c. 208 § 6 places the case in the county where either spouse resides.