After an Illinois divorce is over…it is not really over. Everything in a divorce order can be enforced later in the same Illinois divorce court. Additionally, virtually everything about a divorce order in Illinois can be modified in that same Illinois divorce court.

The world is not static and neither are the lives of the divorced. When a substantial change in circumstances happens in either parties’ lives, one party will file to modify the Marital Settlement Agreement or Allocation of Parenting Time and Parental Responsibilities. If not modified, the other party will fail to meet their obligations under those final documents…which will be followed by a motion to enforce or a Petition For Rule To Show Cause.

This ceaseless return to court can become a Kafkaesque nightmare for Illinois divorce litigants unless either party to the divorce can remind the Illinois divorce court that this matter was ALREADY decided.

As my mother said when I would wine about one of her decisions, “I don’t chew my cabbage twice.”

What Can Be Modified In An Illinois Divorce?

Most matters in an Illinois divorce can be modified. An Illinois divorce is really the resolution of four different issues: 1) Property division, 2) Maintenance (formerly known as alimony), 3) Child Support and 4) Parenting Time/Responsibilities.

Of the above four issues, all except for property division are modifiable.

“[T]he provisions of any judgment respecting maintenance or [child] support may be modified only as to installments accruing subsequent to due notice by the moving party of the filing of the motion for modification.” 750 ILCS 5/510(a)

“Parenting time may be modified at any time, without a showing of serious endangerment, upon a showing of changed circumstances that necessitates modification to serve the best interests of the child.” 750 ILCS 5/610.5(a)

All modifications to child support, maintenance, or parenting time/responsibilities require a “substantial change in circumstances.”

A substantial change in circumstances could be ANYTHING. “There is no precise formula for a substantial change in circumstances.” In re Marriage of Solecki, 2020 IL App (2d) 190381

“The party seeking modification bears the burden of proving this change.” In re Marriage of Logston, 469 NE 2d 167 – Ill: Supreme Court 1984

If the party alleging the substantial change in circumstances proves that the circumstances changed substantially, the other party CANNOT say, “Yeah, well, we actually considered that possible change when we entered into the agreement.” (This used to be the law up until 2022)

For child support and maintenance modifications, “[c]ontemplation or foreseeability of future events shall not be considered as a factor or used as a defense in determining whether a substantial change in circumstances is shown, unless the future event is expressly specified in the court’s order or the agreement of the parties incorporated into a court order” 750 ILCS 5/501(a), 750 ILCS 5/501(a-5)

People who want to change their final divorce orders…really want to change their support obligations. If the would-be divorce order modifier finds out that their alleged change isn’t substantial enough…they will come back with a bigger change sooner or later.

In such a case, the party hoping to preserve the final divorce orders (or the most recently modified divorce orders) should invoke the doctrine of res judicata in order to tell the court “we have already been here and have done that.”

Res Judicata In An Illinois Divorce

Res judicata is “an issue that has been definitively settled by judicial decision.” Black’s Law Dictionary (11th ed. 2019).

Invoking res judicata is effectively telling a court, “we already decided this so we cannot decide it again.”

“Res judicata is an equitable doctrine designed to prevent multiple lawsuits between the same parties where the facts and issues are the same. Under the doctrine, a final judgment on the merits rendered by a court of competent jurisdiction operates to bar a subsequent suit between the same parties and involving the same cause of action.” Lutkauskas v. Ricker, 2015 IL 117090

Asking for the same thing twice is unfair at worst and annoying at best. However, res judicata also covers matters that you COULD have asked for the first time.

“In addition to the matters that were actually decided in the first action, the bar also applies to those matters that could have been decided in the prior suit.” Lutkauskas v. Ricker, 2015 IL 117090

If “the same set of facts was necessary to maintain and prove both cases, the causes of action were identical for purposes of res judicata” Wilson v. Edward Hospital, 2012 IL 112898

The facts must have changed to return to an Illinois divorce court in order to get a modification of an order.

A divorce litigant cannot claim they lost their job in one motion for modification of support, have their modification denied and then come back to court asking for a new modification based on the increased income of the other party if that income had increased at the time of the first motion for modification.

What Is Necessary For A Res Judicata Defense In An Illinois Divorce?

“Three requirements must be satisfied for res judicata to apply: (1) the rendition of a final judgment on the merits by a court of competent jurisdiction; (2) the existence of an identity of cause of action; and (3) identity of the parties or their privies.” Lutkauskas v. Ricker, 2015 IL 117090

In a divorce, the first and third prong of the tests will never be contested. The divorce order was issued and the two spouses remain static parties to that divorce order.

The second prong is governed by a “transactional test” wherein “separate claims will be considered the same cause of action for purposes of res judicata if they arise from a single group of operative facts, regardless of whether they assert different theories of relief.” River Park, Inc. v. City of Highland Park, 184 Ill. 2d 290, 310-11 (1998)

“Under this principle, the dismissal of a single theory of recovery against a particular defendant operates as a final adjudication of all claims based on other theories of recovery that could have been brought as part of the initial action, as long as they arise from the same core of operative facts. Therefore, simply alleging a new theory of recovery is insufficient to assert a different cause of action, where multiple theories of recovery are predicated on the same core of operative facts.” Lutkauskas v. Ricker, 2015 IL 117090

The facts in a divorce modification are always going to be “the same core of operative facts.” There are only so many financial and/or parenting issues between two parties.

Therefore, in an Illinois post-judgment divorce action, a modification can only occur if there has been a substantial change of circumstances since the last time the parties were before the court.

Collateral Estoppel In An Illinois Divorce

A close cousin to the concept of res judicata is collateral estoppel.

Collateral estoppel is “the binding effect of a judgment as to matters actually litigated and determined in one action on later controversies between the parties involving a different claim from that on which the original judgment was based.” Black’s Law Dictionary (11th ed. 2019).

Collateral estoppel also precludes the consideration of matters that were already litigated.

“The doctrine of collateral estoppel provides that an issue which has been addressed by a court of competent jurisdiction cannot be relitigated in a later action between the same parties or their privies in the same or a different cause of action.” Simcox v. Simcox, 546 NE 2d 609 – Ill: Supreme Court 1989

Collateral estoppel is broader than a res judicata in that it does not require a final judgment from the same court. Instead, it can be any matter litigated by any court so long as the facts are the same.

Specifically, collateral estoppel prevents a party from arguing one position in one court and then another position in another court (this could be relevant in simultaneous divorce actions or if one party is in any kind of separate litigation).

Collateral estoppel does not have the same “should have decided” preclusion element that can be invoked in a res judicata defense.

Few things are as satisfying as listening to the same argument from the opposing party for the umpteenth time and merely replying “res judicata” like a wizard invoking an incantation. If you would like to speak with a divorce attorney who knows all these Latin legal terms and how to use them, contact my Chicago, Illinois family law firm to schedule a free consultation.