Are Postnuptial Agreements Enforceable in Massachusetts?

Postnuptial agreements are enforceable in Massachusetts, but a judge will only uphold one if it satisfies all five requirements the Supreme Judicial Court set out in its 2010 decision in Ansin v. Craven-Ansin. The spouse asking the court to enforce the agreement carries the burden of proving every requirement, and the review is stricter than what the same court would apply to a prenuptial agreement or a separation agreement negotiated during divorce.¹

The Five Requirements From Ansin v. Craven-Ansin

Before July 2010, Massachusetts had no clear rule on whether married couples could sign binding contracts dividing their property and support rights. The Supreme Judicial Court resolved the question unanimously in Ansin, holding that postnuptial agreements do not violate public policy and can be enforced if they pass a five-part test.¹

A judge reviewing a postnuptial agreement asks whether:

Each spouse had a genuine opportunity to retain separate counsel. Both spouses do not have to actually hire lawyers, but each must have had the real chance to.
Neither spouse was subject to fraud or coercion in signing.
Both spouses made full financial disclosure of their assets, income, and liabilities, including reasonably anticipated future assets.
Each spouse knowingly and explicitly waived, in writing, the right to a court-ordered equitable division of property and other marital rights.
The terms are fair and reasonable both at the time of signing and at the time a spouse seeks to enforce the agreement.

Miss any one of these, and the agreement is at serious risk. The fifth requirement generates the most litigation because it asks the judge to evaluate fairness at two separate moments in time.

The Second Look at Fairness

An agreement that looked balanced when both spouses signed can look very different ten or fifteen years later. Massachusetts handles that by requiring judges to evaluate fairness twice: once at execution and again at divorce. On the second look, a judge weighs factors similar to those used for separation agreements, including the nature of the objecting spouse’s complaint, the overall financial provisions, the complexity of the original negotiations, and the background and knowledge of each party.¹

The judge may also consider the statutory factors from M.G.L. c. 208, § 34: each spouse’s age, health, income, employability, liabilities, and future earning capacity.² The question is not what a court would have ordered without the agreement. The question is narrower: is this agreement fair and reasonable given current circumstances? If the gap between what the agreement provides and what the spouse would otherwise have received has grown dramatically, that cuts against enforcement.

Why the Scrutiny Is Heavier Than for a Prenup

The Ansin court explicitly refused to treat postnuptial agreements the same as prenuptial ones. The reasoning turns on bargaining dynamics. Before a wedding, either party can walk away from the marriage if the terms feel unfair. After the wedding, that leverage disappears. Spouses owe each other fiduciary-like duties and, in the court’s words, “do not bargain as freely as separating spouses.” A spouse who proposes a postnuptial agreement during a rough patch holds a kind of implicit power that does not exist in arm’s-length negotiations.¹

So the burden sits on the spouse seeking enforcement, and the review is as searching as any Massachusetts family court conducts. Prenuptial agreements get a lighter second look. Postnuptial agreements get the full one.

What the Agreement Can Validly Cover

Within the Ansin framework, spouses can address property division, alimony, and allocation of debts. On property, a postnuptial agreement lets couples opt out of the broad judicial discretion under M.G.L. c. 208, § 34, which otherwise lets a judge assign to either spouse all or any part of the other’s estate, including assets acquired before the marriage, inheritances, and gifts.² Spouses can designate specific assets as separate property, protect a family business, or spell out how a future inheritance will be treated.

On alimony, spouses can set terms that differ from the durational defaults in the Massachusetts Alimony Reform Act.³ They can waive alimony, fix an amount, or agree to something more generous than the statute requires. The one firm limit: a waiver that would leave a spouse reliant on public assistance will likely not be enforced.

Debts incurred during the marriage, including mortgages, student loans, and credit card balances, can also be allocated by agreement. That matters especially when one spouse takes on significant debt for a business or education and the couple wants to keep the other spouse insulated from it in a divorce.

What No Agreement Can Override

Massachusetts courts keep exclusive authority over anything involving a child’s welfare, regardless of what the parents wrote down. Under M.G.L. c. 208, § 31, custody decisions must be guided by the happiness and welfare of the child, and a judge can reject a parental agreement on specific findings that it would not serve the child’s best interests. The same statute makes clear that shared custody does not eliminate a parent’s child support obligation.⁴ A clause trying to waive child support or lock in custody is essentially a dead letter; the court will decide those questions when the time comes.

Provisions that would shift support obligations onto the Commonwealth by leaving a spouse on public assistance are similarly vulnerable, as are terms that read as incentives to divorce or that cut against Massachusetts public policy.

Where Enforcement Most Often Fails: Financial Disclosure

The disclosure requirement is not a formality. It is the element most likely to sink an agreement years after signing. Both spouses must give a complete picture of their financial lives, including current assets, liabilities, and reasonably anticipated future assets and income. In practice, that means assembling bank and brokerage statements, two or three years of federal and state tax returns, deeds and appraisals for real estate, statements for retirement accounts with projected values where available, valuations or financial statements for any privately held business, and a full accounting of debts.

These records are typically compiled into a formal asset schedule attached to the agreement as an exhibit. If a spouse later shows that the other failed to disclose a significant asset or understated its value, that omission can invalidate the entire agreement. This is where most of the actual work of a postnuptial agreement happens, and it is why a solid agreement takes weeks or months to produce rather than days.

Keeping the Agreement Enforceable Over Time

Circumstances shift, and an agreement signed five years ago may not reflect current finances. Massachusetts allows spouses to modify or replace a postnuptial agreement, but any revision must independently satisfy all five Ansin requirements on its own: fresh financial disclosures, a renewed opportunity for each spouse to consult independent counsel, and terms fair and reasonable as of the modification. Crossing out a paragraph and initialing the change will not do it.

Revocation works the same way. Both spouses can agree to cancel the agreement, but the revocation should be in writing and reviewed by each spouse’s attorney. An informal conversation, or an email saying to forget the whole thing, will not reliably undo a formally executed contract. If one spouse later tries to enforce the original terms, the other will need clear evidence that both parties intended to revoke.

1
Justia. Kenneth S. Ansin vs. Cheryl A. Craven-Ansin
2
General Court of Massachusetts. Massachusetts Code Part II, Title III, Chapter 208, Section 34 – Alimony or Assignment of Estate; Determination of Amount
3
General Court of Massachusetts. Part II, Title III, Chapter 208, Section 49
4
General Court of Massachusetts. Part II, Title III, Chapter 208, Section 31