In re Marriage of Sanfilippo, 2025 IL App (1st) 241794-U

Summary

Case Summary: In re Marriage of Sanfilippo, 2025 IL App (1st) 241794-U - Illinois courts treat marital settlement agreements incorporated into dissolution judgments as presumptively valid, placing a heavy burden on the attacking party to prove fraud, coercion, or incompetence—not mere regret or a new attorney's opinion that the deal was unfavorable. The prove-up hearing creates a contemporaneous record of sworn testimony on capacity and voluntariness that effectively forecloses later claims of incompetence, making post-judgment vacatur attempts nearly impossible when both parties testified under oath that they understood and freely entered the agreement.

The opposing counsel already blinked when they assumed their client's post-judgment buyer's remorse would unwind a properly executed marital settlement agreement. In re Marriage of Sanfilippo just reminded every family law practitioner in Illinois exactly how that plays out—and it's not pretty for the party trying to escape their own signature.

This First District appellate decision, while non-precedential under Rule 23, delivers a masterclass in why the prove-up is your fortress and why attacking a settlement agreement after the fact is an uphill battle through a minefield. If you're representing high-net-worth clients in Cook County or anywhere in Illinois, this case is your blueprint for bulletproofing agreements—and your warning shot against half-baked vacatur attempts.

The Setup: A Settlement Under Siege

David Sanfilippo wanted out of his marital settlement agreement. After the dissolution judgment was entered incorporating the MSA, he cycled through counsel and launched a multi-front attack: mental incompetence at signing, alleged statutory violations in the judgment, claims of unconscionability, fraud, and coercion. He even raised procedural objections about the absence of a court reporter.

The trial court wasn't moved. The appellate court affirmed. Every single argument failed.

Here's why this matters to you: the Sanfilippo case crystallizes the standard for vacating an incorporated MSA and demonstrates exactly what happens when a party fails to build their record at the critical moment.

The Legal Standard: Your MSA Is a Fortress (If You Build It Right)

Illinois courts treat marital settlement agreements incorporated into dissolution judgments with substantial deference. The appellate court reiterated the narrow grounds for setting aside such agreements:


    
Fraudulent misrepresentation
    
Coercion or duress
    
Mental incompetence at the time of execution
    
Gross disparity in bargaining power
    
Newly discovered evidence that couldn't have been obtained through due diligence


Notice what's not on that list: regret, a new attorney's opinion that you got a bad deal, or vague claims that you "weren't thinking clearly."

The burden falls squarely on the party seeking vacatur. And that burden is heavy. The trial court's finding that the MSA was "fair, reasonable, not unconscionable, and voluntarily entered" creates a presumption that controls unless the attacking party can marshal compelling evidence to the contrary.

The Prove-Up: Where Cases Are Won and Lost

Here's where Sanfilippo's challenge collapsed: the April 25 prove-up hearing.

Both parties were examined on the record. Both testified under oath that they entered the agreement freely. Both denied any impairment. Both signed a written Certification/Stipulation confirming no contested issues remained. The trial court made an express finding of voluntariness.

When David later brought psychiatric evidence and claimed incompetence, he was fighting against his own sworn testimony. That's not a credibility gap—that's a credibility canyon.

The lesson is surgical: the prove-up is not a formality. It's your insurance policy against exactly this kind of post-judgment attack.

The Prove-Up Protocol for High-Stakes Dissolutions

If you're representing the party who benefits from the settlement holding up, your prove-up should be airtight:


    
Sworn testimony on capacity and voluntariness. Ask your client—and opposing party—direct questions: "Are you under the influence of any substance that impairs your judgment today?" "Have you had adequate time to review this agreement?" "Do you understand what you're giving up and what you're receiving?"
    
    
Written certifications. Get signatures on a stipulation confirming the agreement is voluntary, that both parties have had opportunity for counsel review, and that there are no contested issues. Make it part of the court file.
    
    
Court reporter present—always. Sanfilippo raised the absence of a court reporter as a procedural issue. It didn't save him, but why give opposing counsel any argument? The cost of a court reporter is trivial compared to the cost of relitigating a settlement.
    
    
Express judicial findings. Ask the court to make findings on the record: that the agreement is fair, reasonable, not unconscionable, and entered voluntarily by parties of sound mind. Those findings become your shield on appeal.


The Incompetence Gambit: Why It Almost Never Works

David Sanfilippo's incompetence argument failed for a reason that should inform every family law practitioner's strategy: clinical incompetence sufficient to void a contract requires more than post-hoc psychiatric opinions.

Illinois courts require proof that at the time of execution, the party lacked the mental capacity to understand the nature and consequences of the transaction. That's a high bar when the party:


    
Appeared in court and answered questions coherently
    
Testified under oath that they understood the agreement
    
Signed written documents confirming their voluntary participation
    
Was represented by counsel throughout the process


Post-judgment psychiatric evaluations saying a client was "under stress" or "not thinking clearly" don't overcome contemporaneous evidence of capacity. The Sanfilippo court found that David didn't meet his burden—his later evidence couldn't erase what the record showed at the moment of agreement.

For practitioners: if you genuinely believe your client lacks capacity to enter a settlement, raise it before the prove-up. Request a continuance. Get a psychiatric evaluation. Document your concerns. Once that judgment is entered, you're fighting with one hand tied behind your back.

The Statutory Deficiency Argument: Dead on Arrival

Sanfilippo also argued that the trial court violated statutory requirements by failing to make adequate findings on property values and classification. The appellate court rejected this as well.

Here's the practical reality: when parties enter a negotiated settlement, they're typically waiving the detailed findings that would be required after a contested trial. The agreement itself—if properly drafted—reflects the parties' negotiated positions on value and classification.

But this argument highlights a drafting imperative: your MSA should explicitly state valuations, asset classifications, and the consideration exchanged. Don't leave ambiguity that invites later challenges. If the parties agree that the marital residence is worth a certain amount and is being allocated to one spouse in exchange for other consideration, say so clearly. If certain assets are being treated as non-marital by agreement, document the basis.

This isn't just about surviving appellate review—it's about preventing the challenge from being filed in the first place.

The Timing Problem: Post-Judgment Attacks Face an Uphill Battle

Sanfilippo's substitution of counsel and post-judgment motions came too late to overcome the original record. This is a pattern I see repeatedly: a party signs an agreement, the judgment is entered, and then—often with new counsel whispering that they got a raw deal—they try to unwind everything.

The timing matters enormously:


    
Pre-judgment objections get serious consideration. If you're going to challenge the agreement, do it before the prove-up or during the hearing itself.
    
    
Immediate post-judgment motions (within 30 days, under Section 2-1203) have a fighting chance if you can show genuine grounds.
    
    
Later attacks face the full weight of res judicata, the presumption of validity, and the requirement to show grounds that couldn't have been raised earlier.


For the attorney representing the party who wants the settlement to stand: every day that passes without a challenge strengthens your position. For the attorney whose client is having second thoughts: move fast or accept that the deal is done.

The Cyber-Law Angle: Digital Discovery as Settlement Leverage

Sanfilippo doesn't directly address digital evidence, but the case invites a broader strategic observation: in high-net-worth dissolutions, the discovery phase is where settlements are forged.

When your client has comprehensive documentation of the marital estate—including digital financial records, communications evidencing the other party's understanding of asset values, and metadata showing when documents were accessed or modified—you create the conditions for a settlement that sticks.

Conversely, if the other party has been sloppy with their digital footprint—hiding assets in cryptocurrency wallets they thought were anonymous, communicating about hidden income through "encrypted" apps that aren't as secure as they believed, or failing to preserve electronically stored information—that's leverage. The threat of forensic discovery often brings parties to the table ready to deal.

And once they deal, cases like Sanfilippo show they're unlikely to escape that agreement later.

Practice Imperatives: Protecting Your Client's Settlement

Whether you're drafting the MSA, conducting the prove-up, or defending against a vacatur motion, here's your operational checklist:

At Drafting:

    
Include explicit valuations for all significant assets
    
State the classification (marital vs. non-marital) and the basis for that classification
    
Document the consideration exchanged for any disproportionate allocation
    
Include representations that both parties have had opportunity for independent counsel review
    
Add a provision acknowledging that both parties are entering the agreement voluntarily and with full understanding


At Prove-Up:

    
Ensure a court reporter is present
    
Conduct sworn examination of both parties on capacity, voluntariness, and understanding
    
Obtain signed written certifications
    
Request express judicial findings on fairness, reasonableness, and voluntariness
    
Create a record that forecloses later claims of incompetence or coercion


Post-Judgment:

    
If defending the settlement: oppose any continuances on vacatur motions; emphasize the prove-up record; hold the attacking party to their burden
    
If attacking the settlement: move immediately; gather clinical evidence contemporaneous to the signing if possible; identify specific fraud, coercion, or procedural defects—not just general unfairness


The Strategic Takeaway

Sanfilippo reinforces what experienced family law practitioners already know: the marital settlement agreement, properly executed and proved up, is remarkably durable. The courts are not interested in relitigating negotiated deals because one party later decides they could have done better.

This is exactly why the work you do before and during the prove-up matters more than almost anything else in a dissolution case. Build your record. Document capacity. Get it on the transcript. Make the judicial findings explicit.

When opposing counsel later tries to unwind the deal with claims of incompetence, fraud, or statutory deficiency, you'll have a fortress—and they'll have nothing but regret.



If you're navigating a high-stakes dissolution in Illinois—or facing a post-judgment attack on a settlement agreement—the time to secure experienced counsel is now, not after the prove-up. Book a consultation and ensure your interests are protected with the strategic precision this moment demands.

Full Opinion (PDF): Download the full opinion

Written by Jonathan D. Steele

Chicago divorce attorney with cybersecurity certifications (Security+, ISC2 CC, Google Cybersecurity Professional Certificate). Illinois Super Lawyers Rising Star 2016-2025.

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