How to modify child custody and parenting time in Illinois

Sources last checked 3 November 2026. Information only, not legal advice.

Illinois divorce kit Modifying child support and maintenance in Illinois After your divorce: changing a support or custody order

The short version

The Illinois statute on this does not use the word custody. Section 610.5 of the Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5/610.5) covers changing a “parenting plan or allocation judgment”, meaning the order that divides parental decision-making responsibilities and parenting time. The general test in subsection (c) is that, by “a preponderance of the evidence”, a substantial change has occurred in the circumstances of the child or of either parent, on the basis of facts that arose since the existing order or were not anticipated in it, and that a modification is necessary to serve the child’s best interests. The statute treats parenting time and decision-making slightly differently, and lists situations in which no changed circumstances need be shown. We did not find a statewide standardized form made only for this request. For changing child support or maintenance instead, see modifying child support and maintenance in Illinois.

What must be shown

Parenting time, subsection (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 child’s best interests.
Decision-making responsibilities, subsection (a). Unless the parties stipulate, or section 603.10 applies, a motion to change an order allocating parental decision-making responsibilities, not including parenting time, “may be made earlier than 2 years after its date” only if the court permits it on affidavits that there is reason to believe the child’s present environment may seriously endanger the child’s mental, moral or physical health or significantly impair the child’s emotional development.
The general test, subsection (c). Except where the request is to modify a restriction of parental responsibilities under section 603.10, the court “shall modify” a parenting plan or allocation judgment when necessary to serve the child’s best interests if it finds, “by a preponderance of the evidence”, that on the basis of facts that have arisen since the existing order or “were not anticipated therein”, a substantial change has occurred in the circumstances of the child or of either parent and that a modification is necessary to serve the child’s best interests.
By agreement, subsection (d). The court “shall modify” a parenting plan or allocation judgment in accordance with a parental agreement unless it finds that “the modification is not in the child’s best interests”.
Without changed circumstances, subsection (e). The court may modify “without a showing of changed circumstances” if the modification is in the child’s best interests and one of four things is proven: it reflects the actual arrangement under which the child has been cared for, without parental objection, for the 6 months before the petition was filed (with an exception for acquiescence that was not meaningful consent); it is a minor modification; it is needed to change an agreed plan or judgment the court would not have approved under section 602.5 or 602.7 had it known the circumstances; or the parties agree.
Fees and repeat filings, subsection (f). Attorney’s fees and costs “shall be assessed” against a party seeking modification if the court finds the action is “vexatious or constitutes harassment”. If a parent has repeatedly filed frivolous motions, the court may bar further motions for a period of time.

What the form asks for

On the Illinois courts pages we read, the approved statewide divorce forms are for starting a divorce, and the Motions and Notice page lists a single form, a Motion to Continue (Reschedule) or Extend Time. We did not find a statewide form for changing a parenting plan. The court’s general instructions, How to File and Send a Motion and Notice (ATJ 800.10, 08/25), describe three forms in a set:

Motion: where you explain what you want the judge to do and any reasons why the judge should agree to your request.
Notice of Court Date for Motion: tells the other parties the date, time and place of your court date, and lists the names and addresses of the other parties or their lawyers. The instructions say some courts send their own notice, so ask the Circuit Clerk.
Order on Motion: the form the judge uses to say whether the motion is granted or denied.

The instructions also say “You cannot use a motion to start a new case”, and list civil cases such as divorce and family cases among those where the motion forms may be used. We could not confirm from these sources whether a request to change a parenting plan after a judgment is filed on these forms, so ask the Circuit Clerk or a self-help center before you file.

Filing, notice and what happens next

Hearing: the instructions say that to ask the judge to do something in your case “you must file a motion and have a hearing on the motion”.
Where to file: with the Circuit Clerk’s office in the county where your case is taking place. Most people e-file through Odyssey eFileIL. Some people are not required to e-file or may qualify for an exemption. If you file on paper, the instructions say to bring or send “at least two copies of your forms”, and ask the clerk to stamp your copies and return them.
Court date: ask the Circuit Clerk whether you have to schedule a court date or whether one is scheduled automatically. In some counties you may get the court date when you e-file.
Sending the papers: you must send the forms to the other people in the case, or to their lawyer. If you and the other person each have an email address, the instructions say you must send it by email or through the e-filing system. If either of you has no email address, you may use personal hand delivery, mail or a third-party commercial carrier.
The hearing: the instructions say the court date could be in person, by phone or by video, and to ask the Circuit Clerk how to attend.

Before you file

Filing fees: this page states no amount, because none of the sources we read gives one. The instructions say “There may be a fee to file your Motion”, and that if you cannot afford costs and fees you can ask the court to file for free or at a reduced cost by filing an “Application for Waiver of Court Fees”.
Timing: if you are asking to change decision-making responsibilities, not just parenting time, check the 2-year rule in subsection (a) above and whether an affidavit of serious endangerment would be needed.
The instructions point to Illinois Legal Aid Online, Illinois Court Help (833-411-1121) and local self-help centers. See the Illinois divorce kit for the wider process and for free or low-cost help.
Changing child support or maintenance uses different rules. See modifying child support and maintenance in Illinois.

What we could not confirm

A court form for this request. We found no statewide standardized form for modifying a parenting plan or allocation judgment on the Illinois courts’ divorce, motions and complaint-or-petition pages. We did not search any county circuit court’s own forms, and a county may publish one.
Whether the generic Motion forms are the right route. We read the court’s instructions for them but did not open the Motion, Notice or Order forms themselves, and we cannot say whether a post-judgment request must be a petition or a motion.
Filing fees and service costs. No source we read states an amount.
Other statute sections. We read only section 610.5. We did not read sections 602.5 and 602.7 (parenting plans and the best-interests factors), 603.10 (restrictions on parental responsibilities), or any relocation provisions, so this page does not list the best-interests factors or describe the rules on restrictions and relocation.
The statute’s currency. The text we read ends with its source note, P.A. 99-90 and 99-763. We did not check for later amendments.
How courts apply the test. We did not read case law, so we do not say how courts treat a substantial change, the not-anticipated language or the endangerment affidavit.
Court rules and local practice. We did not read the Illinois Supreme Court Rules or any circuit’s local rules, so we cannot say how mediation, parenting education, notice periods or hearing schedules work in your county.
The Parenting Plan form. The court’s divorce forms include a Parenting Plan, which we saw listed but did not open.

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