Posted on May 10, 2020

Modifying Child Support in Illinois

Child support orders get entered in Illinois when two parents divorce or establish paternity. As the years go by, each parent will make more or less money and the needs of the child will change with time. How does child support get modified in an Illinois divorce or parentage case?

Initial Order Of Child Support In Illinois

Child support is not mandatory in Illinois.  The Illinois statute mandates a lot of things with the heavy-handed word “shall” but when it comes to a divorce, separation, parentage action and even “a proceeding for child support” Illinois courts have the option of awarding child support not the duty to award child support.

“[T]he court may order either or both parents owing a duty of support to a child of the marriage or civil union to pay an amount reasonable and necessary for support.” 750 ILCS 5/505(a)

So, if the two parents decide to waive child support, that’s their business. They do not have to enter into an initial order for child support just because they are getting divorced or establishing a parenting time schedule in Illinois.

However, unless the parenting time and the incomes of the two parties are equal, one of the parents will ask for child support from the other parent. “Both parents have the financial responsibility to support a minor child.” In re Marriage of MacZko, 263 Ill. App. 3d 991, 994 (Ill. App. Ct. 1992)

In making the initial calculation for child support in Illinois, the Illinois statute invokes the Illinois Department of Family Services to create guidelines to establish child support in order to “calculate each parent’s percentage share of the basic child support obligation.” 750 ILCS 5/505(a)(1)(D)

In lieu of explaining the complicated formula that determines child support, I will simply direct you to an Illinois Child Support Calculator where you can estimate child support owed under the Illinois child support guidelines.

Child support in Illinois shall be in the amount calculated by the guidelines unless the court can make a finding (that is, state a specific reason in writing) that the court not use the guidelines amount as child support.

“The court shall determine child support in each case by applying the child support guidelines unless the court makes a finding that application of the guidelines would be inappropriate.” 750 ILCS 5/505

Even then, the Illinois family law court can only deviate from the child support guidelines based on one or more of the following factors:

(A) the financial resources and needs of the child;

(B) the financial resources and needs of the parents;

(C) the standard of living the child would have enjoyed had the marriage or civil union not been dissolved; and

(D) the physical and emotional condition of the child and his or her educational needs.” 750 ILCS 5/505(2)

In my experience, the Illinois child support guidelines are only ever deviated from if the obligor parent’s income is relatively uncertain and the child’s financial needs are certain.  Then, the court will pick a child support amount that is fair to the child and payable by the parent.

Modifying Child Support in Illinois

All child support orders are modifiable no matter what the previous orders say. “[P]rovisions pertaining to child support may not be made nonmodifiable.” In re Marriage of Singleteary, 293 Ill. App. 3d 25, 34 (Ill. App. Ct. 1997)

In order to modify child support in Illinois you must show the court a “substantial change in circumstances” 705 ILCS 5/510(a)(1)

The “substantial change in circumstances” required by the statute will be determined by the court fairly broadly but the circumstances which have allegedly been substantially changed shall be limited to the parents and the child.

“When determining whether there is sufficient cause to modify, courts consider both the circumstances of the parents and the circumstances of the child” Fedun v. Kuczek, 508 NE 2d 531 – Ill: Appellate Court, 4th Dist. 1987

“Only after determining the threshold issue of whether a substantial change in circumstances has occurred can a court consider modifying a child support order.” In re Marriage of Armstrong, 346 Ill. App. 3d 818, 823 (2004)

Proving the substantial change of circumstances is the responsibility of the parent trying to modify child support. In re Marriage of Logston, 469 NE 2d 167 – Ill: Supreme Court 1984

“A substantial change in circumstances typically means that the child’s needs, the obligor parent’s ability to pay, or both have changed since the entry of the most recent support order.” Verhines v. Hickey (In re Marriage of Verhines), 432 Ill. Dec. 293, 310 (Ill. App. Ct. 2018)

You do not have to prove the “substantial change of circumstances” to modify an Illinois child support order “upon a showing of an inconsistency of at least 20%… between the amount of the existing order and the amount of child support that results from application of the [Illinois child support] guidelines” 750 ILCS 5/510(a)(2)(A)

A smaller increase in income will not be sufficient for modification of child support in Illinois. “A substantial change in circumstances may be based solely on an increase in the supporting parent’s ability to pay. However, a small increase in the obligor’s income does not constitute a substantial change in circumstances.” In re Marriage of Connelly, 438 Ill. Dec. 188, 194 (Ill. App. Ct. 2020) (Citations ommitted)

So, if your child support is $ 1000 a month but you calculate based on your income and the other parent’s income that your child support, per the guidelines, should be $ 1200, then you don’t need to show a change in circumstances, the change is proposed support is enough.

Furthermore, “An increase in the child’s needs can be presumed on the basis that the child has grown older and the cost of living has risen. This increase in the child’s needs is balanced against the relative abilities of the parents to provide for those needs.” People ex rel. Stokely v. Goodenow, 221 Ill. App. 3d 802, 805 (1991).

The test for child support modification can also be described as simply as this: “For a modification to occur, there must be a change in the child’s needs, an increase in the father’s income, or a change in the financial condition of the mother.” In re Marriage of Pettifer, 304 Ill. App. 3d 326, 328 (1999)

Any change, though, can also be deemed not sufficient by the court and thus make a motion to modify child support dismissible. “A trial court may eliminate meritless petitions to modify from its docket by the same procedures used in other cases, such as motions to dismiss and motions for summary judgment.” In re Marriage of Pedersen, 237 Ill. App. 3d 952, 957 (1992)

If you are modifying child support in Illinois, expect to follow the guidelines. It is very difficult to modify the child support to a non-guideline amount.

“In any action to…modify child support…the child support guidelines shall be used as a rebuttable presumption for the…modification of the amount of child support. The court may deviate from the child support guidelines if the application would be inequitable, unjust, or inappropriate. Any deviation from the guidelines shall be accompanied by written findings by the court specifying the reasons for the deviation and the presumed amount under the child support guidelines without a deviation.” 750 ILCS 5/505(a)(3.4)

If you are requesting a non-guidelines child support amount, you’ll have to convince the Illinois family law judge of your reasons for ordering non-guidelines support so well, that the Illinois family law judge will be willing to put those reasons in writing.

How To Modify Child Support In Illinois

In order to modify child support in Illinois, you must file a motion to modify child support where you cite the appropriate statute, 750 ILCS 5/510 and lay out the reasons why you should be entitled to a modification in child support.

Your child support will only be modified as of the date of notice of filing to the other parent. Anything owed before that date, will remain owed at the previous rate of child support no matter how long the circumstances have been substantially changed.

“[S]upport 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

While the statute says “due notice,” most courts just use the date of filing and don’t focus on actual notice.  It’s the year 2020 and it is presumed you have your children’s other parent’s email address an gave them notice via email.  You do not have to serve someone with notice in order to modify child support in Illinois. The case already exists so formal service is not necessary any longer.

Once your motion to modify child support is set before a judge in Illinois, you can request a “summary hearing.” These are usually reserved for temporary motions for child support before the matter is initially finalized but they are so quick and useful, an Illinois judge will be likely to use the same method for a motion for modification of child support.

A summary hearing is just the judge comparing the parties’ respective financial affidavits and supporting documents to determine the current respective incomes and what child support should be pursuant to those amounts. This takes 5 minutes of an Illinois family law judge’s time and is devoid of drama.

If the other parent objects to the “summary hearing” you’ll have to have a full hearing that involves the formal introduction of evidence and testimony of the parties.

What If I Don’t Know The Other Parent’s Income?  How Do I Calculate Child Support For The Purposes Of Modification?

When you finalized the child support award in the initial final divorce decree and/or allocation of parenting time and parenting responsibilities, there should have been a clause included in one of those documents that orders the parties to exchange tax returns, W2s and 1099s to verify their respective incomes.

If there is not a clause that requires the regular exchange of financial information, then you can simply request that information.  If the other parent does not provide that financial information, then you can file a motion to modify child support based on “information and belief that the financial circumstances of the party has changed as they did not respond to my request for updated financial documents.”

In the final hearing for modified child support, the other parent will be required to fill out and exchange the Illinois financial affidavit which will include those originally requested documents.

“In all post-judgment proceedings in which a party is seeking to establish, modify or enforce an order of…child support… the parties shall exchange a completed “Financial Affidavit”” Cook County Court Rule 13.3.1(b)

What If The Change In Circumstances Is Voluntary?

If one parent quits their job and is making less money than they previously did that is certainly a substantial change in circumstances that could warrant a modification of child support.

Under Illinois case law, there is a big exception to this rule.  The court will not reward someone who voluntarily makes less money by granting a modified child support order that reflects the voluntary change in circumstances.

“It is well established that a voluntary change in occupation or employment made in good faith may constitute a material change in circumstances sufficient to warrant modification of a child support order.

The crucial consideration in testing “good faith” is whether the change in status was prompted by a desire to evade financial responsibility for supporting the children or to otherwise jeopardize their interests.” Coons v. Wilder, 416 N.E.2d 785, 93 Ill.App.3d 127, 48 Ill.Dec. 512 (Ill. App. 1981)

A lot of changes in income are voluntary but are also the result of broader forces.  For example, opening a business that lost money during a recession. 

“Substantial economic reverses resulting from investments or employment are proper circumstances to be considered in determining whether child support might be reduced or terminated.

The change in circumstances must, however, be fortuitous in nature and not the result of deliberate action or conduct of the party seeking the reduction.” Coons v. Wilder, 416 N.E.2d 785, 93 Ill.App.3d 127, 48 Ill.Dec. 512 (Ill. App. 1981)

So, to modify child support there must have been a change in income that was not motivated primarily by the desire to reduce your child support. 

In order to modify child support in Illinois, you are allowed to be unlucky, unwise and even foolish. You are just not allowed to be selfish.

How Does Child Support In Illinois Change If The Child No Longer Lives With One Parent?

One of the factors that determines the amount of child support is the amount of time the child spends with each parent.  The parent who has the child the majority of time receives child support from the parent who has the child the minority of time.

What’s more if the parent who has the child the minority of the time has over 146 overnights with the child, that parent will get a reduction in their child support.

Any actual shift in parenting time that changes who is, in fact, the parent with the majority of parenting time or if the non-primary parent is actually exercising more than 146 overnight visits shall constitute a substantial change in circumstances for the purposes of modifying child support.

“A change of custody is itself a substantial change in circumstances.” Marriage of White, In re, 561 N.E.2d 1387, 204 Ill.App.3d 579, 149 Ill.Dec. 691 (Ill. App. 1990)

A mere change in parenting time below the 146 night threshold does not, in itself, create a substantial change in circumstances.

“While it may seem implicit that an increase in parenting time automatically includes an increase in expenses for the parent exercising additional time, trial courts are not in the position to make such bold assumptions. Absent a drastic change in parenting time, a mere increase in parenting time for one parent does not necessarily result in the reduction of the financial burden associated with raising the child for the other.” In re Marriage of Wengielnik, 2020 IL App (3d) 180533

How Do You Modify Child Support In Illinois If A Child Turns 18?

A child may become an adult in the eyes of Illinois law at age 18 but you child support doesn’t necessarily end on that birthday. 

“[T]he term “child” shall include any child under age 18 and any child age 19 or younger who is still attending high school.” 750 ILCS 5/505(a)

All child support orders shall include a termination date that reflects when the child turns 18, 19 or graduates from high school in between.

“An order for support shall include a date on which the current support obligation terminates. The termination date shall be no earlier than the date on which the child covered by the order will attain the age of 18. However, if the child will not graduate from high school until after attaining the age of 18, then the termination date shall be no earlier than the earlier of the date on which the child’s high school graduation will occur or the date on which the child will attain the age of 19.” 750 ILCS 5/505(g)

So, you don’t need to go back to court to modify child support if you only have one child.  But you will need to go back to court to modify your child support if you have children younger than the one who just became an adult. 

What About Modifying Children’s Expenses In Illinois

Child support is rarely, if ever, the only financial obligation that a parent has to a child.  The allocation of parenting time and parenting responsibilities should outline expenses that each parent will pay for on behalf of the child as they relate to education, health, religion and extracurricular activities

These expense obligations can also be modified should there be a substantial change in circumstances.

“An order for child care expenses may be modified upon a showing of a substantial change in circumstances. The party incurring child care expenses shall notify the other party within 14 days of any change in the amount of child care expenses that would affect the annualized child care amount as determined in the support order.” 750 ILCS 5/505(3.7)(D)

Coming To An Agreement Regarding Child Support Modification In Illinois

Going to court every few years to modify child support and/or children’s expenses is a cumbersome task. Parents would be well advised to try to come to an independent agreement regarding child support that does not involve the Illinois domestic relations court formally taking evidence and calculating child support obligations. 

If the parents do come to an out-of-court agreement regarding child support, the court must approve that agreement and enter into an order.

“[P]arents may create an enforceable agreement for modification of child support only by petitioning the court for support modification and then establishing, to the satisfaction of the court, that an agreement reached between the parents is in accord with the best interests of the children.” Blisset v. Blisset, 526 NE 2d 125 – Ill: Supreme Court 1988

The child support is for the child, not the parents. Therefore, the court must be sure than any agreement regarding the child remains in that child’s best interests.

In my experience, Illinois divorce courts will always happily enter any reasonable on-its-face agreement.  Even if the court has questions about your agreement, satisfying the court’s curiosity about your agreement is as easy as simply answering those questions. 

If both parents simply agree on a handshake or written contract that is NOT a court order and never go to court again, either parent can return to court with the original order and ask that the original order be enforced.

The original order will be enforced despite the out-of-court agreement.

“[E]xtrajudicial agreements modifying support are unenforceable” In Re Marriage Of Smith 806 N.E.2d 727 (Ill. App. Ct. 2004)

The only way to enforce an out-of-court agreement regarding child support is to show that one party relied on that agreement to their detriment.  This is called “Equitable Estoppel”

“Equitable estoppel applies when a person, by his or her statements or conduct, induces a second person to rely, to his or her detriment, on the statements or conduct of the first person. The party asserting estoppel must have relied upon the other person’s acts or representations” In Re Marriage of Case, 351 Ill.App.3d 907, 286 Ill.Dec. 857, 815 N.E.2d 67 (Ill. App. 2004)

So, if you had an out-of-court agreement that modified child support but ALSO modified something else and you followed through on it, your out-of-court child support modification will be held as valid by the Illinois courts.

For example, if you had a handshake deal that reduced child support in exchange for paying for all of the extra-curricular activities and you did, in fact, pay for those extracurricular activities, then your handshake deal will be enforceable.

If you’d like to modify your child support in Illinois or your children’s other parent is trying to modify your child support, contact my Chicago, Illinois family law office to speak with an experienced Chicago divorce lawyer.

Share Article on


Russell Knight

Russell D. Knight has been practicing family law as a Chicago divorce lawyer since 2006. Russell D. Knight amicably resolves tough cases while remaining a strong advocate for his client’s interests.

More about This Topic

Relevant Articles

Call Now Button