Prenuptial and Postnuptial Agreements

This guide is for informational purposes only and is not legal advice. For advice about your specific situation, consult a licensed Colorado family law attorney.

Your Situation

If you or your spouse signed a prenuptial agreement (an agreement made before marriage) or a postnuptial/marital agreement (one made after you were already married), that document can change how your divorce plays out. These agreements can remove certain assets from the pool of property a court divides, and they can address — or even waive — spousal maintenance (alimony). In other words, they can override some of the default rules that would otherwise apply.

That makes the agreement one of the most important pieces of your case. A valid agreement generally binds both of you to its terms, and Colorado courts tend to favor enforcing them. But "generally" is not "always" — there are specific, recognized grounds for challenging an agreement, and whether one applies to you depends heavily on the facts of how the agreement was made. This guide will help you understand what the law requires for an agreement to hold up, when and how an agreement can be challenged, and the concrete steps to take whether you want to enforce yours or set it aside.

What the Law Requires

Colorado law lets couples contract in advance about property and maintenance, and it does not treat these agreements as against public policy. Property that a valid agreement excludes from the marital estate simply is not marital property, so the court does not divide it. Couples are allowed to make agreements that anticipate the possibility of divorce and fix property rights ahead of time, regardless of how long the marriage lasts.

A critical formal rule: an agreement that excludes property from the marital estate must be in writing and signed by both spouses. An oral promise during the marriage to keep something — like a retirement account or an inheritance — out of the marital estate is not valid, and the couple's later conduct does not substitute for the required writing.

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If your agreement about property was never put in writing and signed by both of you, Colorado courts have held it cannot exclude property from the marital estate.

The law treats several types of documents differently, and which one you have matters:

• A premarital (prenuptial) agreement is between two people who intend to marry. It takes effect on the wedding date.
• A marital (postnuptial) agreement is between people already married who intend to stay married. It takes effect when both parties sign it. A marital agreement does not need prior court approval to be enforceable.
• A separation agreement is signed when divorce or separation is anticipated or pending. Even if signed before a case is filed, an agreement made "attendant upon" a contemplated divorce is treated as a separation agreement — and separation agreements are judged under a different, more flexible fairness standard than prenuptial agreements.

Maintenance deserves special attention. Colorado law permits spouses to contract about maintenance in a prenuptial agreement, and there is no blanket prohibition against it. But an agreement does not bar a maintenance claim unless it specifically waives maintenance — silence on the subject means the statutory maintenance rules apply. And even a validly signed maintenance waiver can be set aside as unconscionable based on the circumstances at the time of the divorce. Unconscionability here means enforcing the terms would leave a spouse without enough property to meet reasonable needs and unable to support themselves through appropriate employment.

Two other points from the law: a waiver of attorney fees inside one of these agreements can be reviewed and voided for unconscionability; and where an agreement is silent on an issue like property distribution or attorney fees, the governing statutes fill the gap.

What Courts Typically Do

In practice, Colorado courts favor enforcing prenuptial agreements, which means the person trying to get out of one carries the burden of proving it should not apply. A disproportionate result — even most of the marital assets going to one spouse — does not by itself invalidate an agreement. Courts are required to enforce an unambiguous agreement according to its terms, including terms about how increases in the value of separate property are treated.

Importantly, challenges to a prenuptial agreement's validity focus on how it was formed, not on whether its terms turned out to be fair. In practice, the grounds a court looks at depend on which law governs the agreement:

• Under the older Colorado Marital Agreement Act, a marital agreement can be attacked on two grounds: that it was not entered voluntarily, or that the challenging party did not get fair and reasonable disclosure of the other's property and financial obligations before signing.
• Under the newer Uniform Premarital and Marital Agreements Act (effective July 1, 2014), there are four grounds — the first being that consent was involuntary or given under duress.

The agreement's effective date determines which Act applies, so the timing of signing and marriage matters. If an agreement is governed by another state's law, that state's law controls its validity.

Courts give extra scrutiny when a spouse appears to have consented under emotional stress or without a lawyer. And an itemized list of assets is not strictly required, as long as the amount of a party's assets was not materially misstated. Validity challenges are fact-intensive and almost always require an evidentiary hearing. A judge has discretion to decide the validity question first (called bifurcating), which can narrow the dispute before the parties spend time and money on everything else.

One distinction worth knowing: challenging the property-division terms of a separation or settlement agreement requires showing both unconscionability and fraud or overreaching — a higher bar than challenging maintenance terms. Because these agreement types are legally distinct, don't assume a document you have addresses something it doesn't.

Step by Step: What to Do

1. Locate the actual signed agreement. Find the fully executed document with both signatures, plus any attachments or financial disclosures that went with it. Note the date it was signed and your wedding date — these determine which law governs and when the agreement took effect.

2. Figure out what kind of agreement it is. Was it signed before the wedding (premarital), during a stable marriage (marital/postnuptial), or when a split was already being contemplated (which would make it a separation agreement judged differently)? This classification drives everything else.

3. Read exactly what it covers. Check whether it addresses property, maintenance, or both — and whether it contains a specific waiver of maintenance or attorney fees. Remember that silence on maintenance means the statutory rules apply instead.

4. Decide your goal: enforce it or challenge it. If you want to enforce it, you'll be relying on Colorado's general tendency to uphold these agreements. If you want to challenge it, identify your grounds — focus on how it was formed (voluntariness, duress, disclosure) rather than simply that the result feels unfair.

5. Gather your evidence. Collect anything showing the circumstances of signing: when you first saw the document, whether you had your own lawyer, what financial information was disclosed, and any pressure around the signing. Be prepared to document all written and oral terms, any later modifications, any breaches, and any grounds for unenforceability — these are exactly the kinds of questions the other side can ask you about in writing during the case.

6. Start your divorce paperwork. You don't need to hunt down and hand-fill blank court forms. The guided wizard on this site will interview you about your situation and prepare and pre-fill the correct Colorado forms for you, including the petition and the documents needed to formally serve the other party.

7. Raise the agreement issue early and in writing. If you believe you signed under pressure or without understanding the terms, raise that with the court before a final order is entered. Expect that resolving a validity dispute will likely involve an evidentiary hearing, and consider asking the court to decide the validity question first.

8. Consider consulting a family law attorney. Because validity turns on fact-specific details and the governing law differs depending on timing, this is an area where tailored legal advice can matter a great deal.

What Research Shows Can Help

The items provided here focus on the law and court practice around prenuptial and postnuptial agreements and do not include social science research findings on this specific topic. Because of that, there's nothing from the materials I can responsibly present as research-based guidance here. If you have children and co-parenting is part of your case, research-based guidance may be available in the related articles on parenting issues.

What to Do Today

• Find and set aside the signed agreement, any financial disclosures attached to it, and note both the signing date and your wedding date.
• Write down, while it's fresh, what you remember about how and when you signed — whether you had a lawyer, how much time you had, and what you were told about the other person's finances.
• Decide whether your aim is to enforce or challenge the agreement, and jot down the specific reasons.
• Start the guided wizard to begin preparing your divorce paperwork so the agreement issue can be raised in your case.
• If possible, schedule a consultation with a Colorado family law attorney to review the agreement's enforceability.

Related Issues to Be Aware Of

• Property division: Your agreement interacts directly with how the court divides assets. Anything a valid agreement properly excludes is set aside and not divided; anything it doesn't cover falls back to the default rule that property acquired during the marriage is presumed marital and divided equitably. Watch for property your agreement is silent about — the statute will govern it.

• Spousal maintenance: If your agreement doesn't specifically waive maintenance, the court applies the standard maintenance analysis, including findings on income, resources, and need, and the advisory guidelines for qualifying marriages. Even a signed waiver can be set aside as unconscionable based on your circumstances at the time of divorce.

• Debt allocation: Agreements often focus on assets, but debts matter too. If your agreement is silent on debt, the court applies the usual rules — debt acquired during the marriage is generally marital, though a judge can assign repayment to the spouse who incurred it.

• Legal separation vs. divorce: The same agreement issues arise whether you pursue a divorce or a legal separation, since both use the same statutory findings. Keep in mind that a document signed when a split was already being contemplated may be treated as a separation agreement — and judged under a more flexible fairness standard — rather than as a prenuptial or marital agreement.