Illinois has not used the word "custody" in a judgment since 2016. What replaced it, the allocation of parental responsibilities, changed more than terminology: decision-making authority and parenting time are now argued and awarded separately, each on its own evidence. This guide covers how allocation actually works, from the best-interests factors to relocation and modification.
From "Custody" to "Allocation of Parental Responsibilities"
Before 2016, Illinois law spoke of "custody" and "visitation," terms most parents searching for help still use, and terms attorneys and pop culture never fully retired. The Illinois Marriage and Dissolution of Marriage Act now uses different language on purpose. Courts allocate significant decision-making responsibility, meaning authority over a child's education, health care, religion, and extracurricular activities, and they allocate parenting time separately. A parent can hold equal parenting time without equal decision-making authority, or the reverse.
The distinction is not academic. A settlement or judgment that only addresses a schedule and says nothing about decision-making leaves a real gap, one that tends to surface at the worst possible moment: a medical decision, a choice of school, a disagreement over a religious upbringing. Allocation judgments have to answer both questions, separately and specifically.
The Best-Interests Factors Under 750 ILCS 5/602.5 and 602.7
Illinois courts do not have discretion to decide allocation on instinct. Sections 602.5 and 602.7 of the Illinois Marriage and Dissolution of Marriage Act set out the factors, and they are gender-neutral on their face: each parent's wishes, the child's own wishes weighted by age and maturity, how much caretaking each parent has actually performed over the past two years, the child's adjustment to home, school, and community, the mental and physical health of everyone involved, and each parent's willingness to facilitate a close relationship between the child and the other parent.
No single factor controls, and courts do not average them. In practice, caretaking history and the willingness-to-facilitate factor tend to carry outsized weight, because both are provable with records, texts, calendars, and school and medical contacts, rather than with testimony alone. Parents who can document their involvement, and their cooperation, consistently do better than parents who can only assert it.
Parenting Plans: What Illinois Requires
Illinois requires each parent in a case involving minor children to file a proposed parenting plan, typically within 120 days of the case being filed. The plan has to address the practical mechanics of raising the child across two households: the schedule, holidays, decision-making authority, communication between the parents, and a process for resolving future disagreements without returning to court for every one.
If the parents agree, the court reviews and enters the plan largely as submitted. If they do not, the court holds a hearing and enters its own allocation judgment based on the statutory factors. Cook County also requires most parents in contested cases to attempt mediation on parenting issues before litigating them, and to complete a parenting education program before judgment. Neither requirement is a formality. An unresolved mediation referral or an unfinished class is one of the more common, and more avoidable, reasons a case stalls short of judgment.
Guardians ad Litem and Child Representatives
In contested cases, the court frequently appoints a guardian ad litem or child representative under Section 506 of the Act. The appointee investigates, typically interviewing both parents, the child where appropriate, teachers, and other relevant witnesses, and reports a recommendation to the court. Courts give these reports substantial weight, which makes the investigation itself a phase of the case, not a formality that happens between the real hearings.
Courts can also order a more formal custody evaluation under Section 604.10, usually performed by a mental-health professional, in cases involving allegations of abuse, substance use, or mental illness. Parents who treat the guardian ad litem's process as a box to check, rather than as an audience to persuade, routinely get outcomes they did not expect.
Relocation: Moving With Children After a Case
Illinois requires notice, and often court approval, before a parent with the majority of parenting time can relocate with the children beyond specific distance thresholds. Within Cook County and the collar counties, that threshold is a move of more than 25 miles from the child's current residence. From other Illinois counties, the threshold is more than 50 miles. A move out of state of more than 25 miles also qualifies, regardless of which county the family currently lives in.
A relocation petition is decided under its own best-interests factors, related to but distinct from the standard allocation factors: the reasons for the move, the reasons for any objection, the history of the parties' compliance with the existing parenting plan, and whether a revised schedule can reasonably preserve the other parent's relationship with the child. These cases are heavily fact-driven, and they are worth litigating properly on both sides of the petition.
Modifying an Existing Allocation Judgment
Parenting time can be modified when a parent shows a substantial change in circumstances and demonstrates that modification serves the child's best interests. Illinois sets a higher bar for changing decision-making allocation within the first two years after judgment, generally requiring a showing that the child's current environment seriously endangers their physical, mental, or emotional health, unless both parents agree to the change.
Informal adjustments that both parents follow are common and, for many families, work fine, right up until they do not. Only a modified court order is enforceable. A parent relying on a verbal understanding rather than an updated judgment has no recourse when the other parent simply stops honoring it.
Unmarried Parents: Paternity Comes Before Allocation
Everything above assumes parentage is already established. For unmarried parents, it is not automatic. A biological father has no enforceable right to parenting time or decision-making, no matter how involved he has been, until parentage is legally established under the Illinois Parentage Act, whether by a Voluntary Acknowledgment of Paternity, a presumption, or a court adjudication. Once parentage is established, the same allocation framework and best-interests factors described above apply without regard to the parents' marital history.
Fathers and the Best-Interests Standard
Illinois' allocation statute contains no preference for mothers, and has not for years. Where fathers end up with a minimal schedule, it is typically because they accepted one early in a case, often on the mistaken belief that the law favored the mother, rather than because a court weighed the evidence and ruled against them. The best-interests factors reward the parent who can document caretaking and cooperation, regardless of which parent that is.