Senate Bill 3524, titled “Child Support Changes” on the Illinois General Assembly’s website, passed both the Senate and the House of Representatives on May 21, 2026. Set to go into effect January 1, 2027.
Senate Bill 3524 provides for amendments to Sections 505 and 510 of the Illinois Marriage and Dissolution of Marriage Act, provisions establishing the procedure for calculating and modifying child support obligations. These amendments provide significant changes to the current child support formula and the analysis of the factors used to determine child support. The amendments also address determination of child support for low-income and incarcerated obligors. Parents and practitioners alike should prepare themselves for the impact Senate Bill 3524 may have on both newly established and already existing child support obligations beginning in 2027.
The existing law under Section 505 of the Illinois Marriage and Dissolution of Marriage Act uses a “shared care” framework to calculate each parent’s child support obligation based on their respective incomes. Section 505 currently requires each parent exercise at least 146 overnights annually for this framework to apply. If this threshold is met, the parents’ incomes are combined to determine the basic support obligation based on the number of children at issue. The calculated obligation is then multiplied by 1.5, and each party’s respective obligation is determined based on an offset of his or her share of the combined income and percentage of overnights.
If a parent exercises less than 146 annual overnights, the calculation shifts to a traditional approach which substantially impacts the resulting child support obligation. There is no 1.5 multiplier nor is there an adjustment based on respective incomes or share of overnights. In these instances, parenting time has a limited effect on the guideline support obligation, whether 145 overnights are exercised or greatly less. Thus, under the current law, the 146-overnight threshold often proves to be a significant area of dispute amongst parents due to the major impact it has on how much child support is owed. One of the primary goals of Senate Bill 3524 is to address the major consequences this threshold presently has on child support calculations by expanding the analysis of shared parenting time beyond the current threshold approach.
One of the most significant changes provided by Senate Bill 3524 is a lowered threshold in cases where physical care of the child(ren) is shared.
Beginning January 1, 2027, the new threshold to trigger the “shared care” approach for calculating child support is set at 110 annual overnights or the newly introduced “overnight equivalents.” This change acknowledges that respective parenting responsibilities may not be accurately depicted by solely looking at overnights. Under this amendment, a court may find the new 110-overnight threshold is met, even if less than 110 overnights are exercised, after analyzing each parent’s specific parenting time and responsibilities in totality. This change may significantly impact the contention around parenting-time schedules and the financial consequences the current threshold has.
Major Change #2: Recognition of Overnight Equivalents
- Definition of overnight equivalents.
- Application to parenting schedules involving:
- Extended daytime parenting.
- Split-week schedules.
- Nontraditional work schedules.
- Potential areas for litigation and judicial discretion.
Major Change #3: New Shared-Care Child Support Formula
- Multiplication of the basic child support obligation by 1.5.
- Allocation based upon each parent’s share of combined adjusted net income.
- Offset calculation between parents.
- New statutory adjustment table for parents with fewer than 146 overnights/equivalents.
- Limitation preventing shared-care support from exceeding the amount that would be ordered under the standard guidelines.
Major Change #4: New Minimum Child Support Presumption
- Rebuttable presumption of $40 per month per child.
- Applies to obligors at or below 100% of the federal poverty guidelines.
- Comparison to current treatment of low-income obligors.
- Potential effects on modification proceedings.
Major Change #5: Incarcerated Parents
- New presumption that a parent incarcerated for more than 180 days is unable to pay child support.
- Rebuttable nature of the presumption.
- Practical implications for modification petitions and arrearages.
Major Change #6: Annual Income Exchange Requirements
- Requirement that child support orders include annual income disclosures.
- Requirement to notify the other parent and the clerk within 10 days of:
- New employment.
- Employment termination.
- Information that must be provided.
- Potential impact on enforcement and future modifications.
Practical Impact for Illinois Parents
For Parents with Near-Equal Parenting Time
- Potential increase or decrease in support obligations.
- Importance of accurately documenting parenting time.
For Parents Seeking Modifications
- Whether existing orders may warrant review after January 1, 2027.
- Anticipated litigation concerning overnight equivalents.
For Family Law Practitioners
- Need to analyze parenting schedules more carefully.
- Importance of advising clients regarding employment-reporting obligations.
Conclusion
- SB 3524 represents the most significant child support revision since Illinois adopted the income-shares model.
- Shared parenting arrangements will receive greater statutory recognition.
- Parents and practitioners should prepare for implementation before January 1, 2027
