How to Modify Parental Responsibilities or Parenting Time in Illinois

When can you modify in Illinois?

Under 750 ILCS 5/602.10, the court can modify an existing allocation of parental responsibilities or parenting time order when there has been a substantial change in circumstances since the last order was entered. The burden is on the parent requesting the modification to demonstrate that such a change has occurred and that modification is in the best interest of the child.

The standard for modification is different depending on whether the request comes within two years of the last order or after two years. Illinois law creates a higher bar within the first two years specifically to prevent parents from relitigating parenting arrangements shortly after they are set.

The two-year restriction

Within two years of the entry of the last parenting order, the court will not modify allocation of parental responsibilities unless the petitioner can show that:

• The child's present environment seriously endangers the child's physical, mental, moral, or emotional health; or
• The parties agree to the modification in writing.

After two years have passed, the standard drops to a substantial change in circumstances — a significantly lower bar. A parent does not need to show serious endangerment; they need only show that circumstances have materially changed since the last order and that modification serves the child's best interest.

Parenting time (as distinct from allocation of responsibilities) can be modified at any time without the two-year restriction, as long as there is a substantial change in circumstances and modification is in the child's best interest.

What counts as a substantial change in circumstances?

Illinois courts have recognized the following as potential substantial changes in circumstances for modification purposes:

• Relocation — a parent moving a significant distance (Illinois has a separate relocation statute for moves over 25 miles for Cook, DuPage, Kane, Lake, McHenry, and Will counties, or over 50 miles for all other counties).
• Significant schedule changes — a parent's new work schedule that makes the current parenting time arrangement impractical.
• Change in child's needs — a new diagnosis, educational needs, or medical condition requiring different arrangements.
• Domestic violence — a pattern of violence or abuse that has emerged since the last order.
• Substance abuse — a parent developing a substance abuse problem after the last order.
• Child's preference (age 14+) — courts give significant weight to the stated preferences of teenagers, though it is not determinative.
• Parent's failure to follow the order — repeated, documented violations of the existing parenting schedule.

How to file a Petition to Modify

To modify allocation of parental responsibilities or parenting time in Illinois, follow these steps:

1. File in the original circuit court — modifications must be filed in the same circuit that entered the original order, unless the court has transferred jurisdiction.
2. Complete the Petition to Modify — identify the order you are seeking to modify, state the substantial change in circumstances, and specify what modification you are requesting.
3. Attach a supporting affidavit — your petition must be supported by a sworn affidavit setting out the factual basis for the modification.
4. Pay the filing fee — filing fees vary by circuit. If you cannot afford the fee, apply for a fee waiver (Application to Sue or Defend as an Indigent Person).
5. Serve the other parent — the respondent must be personally served with the petition and summons. They have 30 days to respond.
6. Attend temporary orders hearing if needed — if there is an emergency, you can request a temporary order to address the situation while the full case proceeds.

Modifying child support separately

Child support is modified under 750 ILCS 5/510, not 750 ILCS 5/602.10. You can request a child support modification if: (1) there has been a substantial change in the financial circumstances of either parent or the needs of the child, or (2) three years have passed since the last support order was entered and the new amount would differ by at least 20% or $10 per month, whichever is greater.

The Illinois Department of Healthcare and Family Services (BCSE) reviews child support orders every three years upon request of either parent. You can request a review through BCSE without filing a court petition, though ultimately a judge must enter the new order.