Illinois Child Support Law Gets A Major Update In 2027: What Parents Need To Know

Illinois parents involved in divorce, parentage, or child support proceedings should be aware of important changes coming to the state's child support laws. On July 31, 2026, Governor J.B. Pritzker signed Senate Bill 3524 into law as Public Act 104-733. The new law amends Sections 505 and 510 of the Illinois Marriage and Dissolution of Marriage Act (IMDMA) and becomes effective January 1, 2027.

While the legislation does not replace Illinois' income-shares model for calculating child support, it makes several meaningful changes designed to improve fairness, recognize modern parenting arrangements, and provide greater clarity when support orders are established or modified.

Expanded Protection for Low-Income Parents

One of the most significant changes involves Illinois' minimum child support obligation.

Under prior law, there was a rebuttable presumption that a parent earning 75% or less of the federal poverty level would be ordered to pay a minimum of $40 per month per child, up to a maximum of $120 per month.

Beginning January 1, 2027, that income threshold increases to 100% of the Federal Poverty Guidelines. In practical terms, more very low-income parents will qualify for the minimum support obligation rather than having support calculated under the standard income-shares guidelines.

The law continues to recognize that some parents simply lack the financial ability to pay support. Parents with no income, those receiving only means-tested public benefits, or those unable to work because of a medically documented disability, incarceration, or institutionalization remain subject to a rebuttable presumption that a zero-dollar support order is appropriate.

A More Refined Approach to Shared Parenting

The new law also makes a noteworthy change for families who share parenting time.

Illinois has long recognized "shared physical care" when each parent exercises at least 110 overnights per year with the child. Previously, the shared parenting calculation applied the same formula to every qualifying case.

Public Act 104-733 introduces a more nuanced approach by creating graduated adjustments for parents who exercise between 110 and 145 overnights each year. Depending on the number of overnights, the support calculation now includes an adjustment ranging from 10% for 110-114 overnights down to 2% for 140-145 overnights.

Once each parent reaches 146 or more overnights, the traditional shared parenting formula continues to apply without the graduated adjustment.

This change better reflects the reality that parenting time exists on a spectrum rather than as an all-or-nothing calculation.

Greater Clarity for Child Support Modifications

Public Act 104-733 also clarifies when existing child support orders may be modified.

The amended statute provides that a court may modify child support upon a substantial change in circumstances and specifically states that the mere fact a future event was foreseeable does not prevent modification. Foreseeability is only relevant if the parties' agreement or the court's order expressly identifies a future event and states that it will not constitute a substantial change in circumstances.

This clarification should reduce disputes over whether changes in employment, income, or other anticipated life events automatically bar a request to modify support.

New Procedure for Parents Who Are Incarcerated

Another important addition addresses child support obligations during lengthy periods of incarceration.

The law creates a streamlined administrative procedure for parents who will be incarcerated for more than 180 consecutive days.

Under the new process:

A notice of incarceration may be filed with the court.

If no objection is filed within 45 days, the child support obligation is automatically modified to $0.00 by operation of law.

Following the parent's release, support automatically resumes at the statutory minimum amount 90 days after release, unless another modification is sought based on the parent's actual ability to pay.

If another party believes the incarcerated parent has sufficient assets or income to continue paying support, that presumption may be challenged through a court hearing.

These provisions are intended to prevent unrealistic child support arrearages from accumulating when a parent has no meaningful ability to earn income during incarceration.

Other Technical and Procedural Updates

The legislation also includes several technical revisions designed to improve consistency in child support proceedings. Among other things, the Act updates statutory language regarding annual income disclosures, employment reporting, shared parenting worksheets, and procedures used by the Illinois Department of Healthcare and Family Services.

While many of these revisions are procedural, they should help courts apply the child support guidelines more consistently across the state.

What This Means for Illinois Families

The new law does not automatically change existing child support orders. Parents with current support obligations must still obtain a court order to modify support unless a specific statutory provision provides otherwise.

However, parents considering filing for divorce, establishing parentage, or seeking a modification after January 1, 2027, should understand how these amendments may affect the calculation of support.

In particular, families with lower incomes, parents who exercise substantial—but not equal—parenting time, and parties seeking to modify existing support orders may see the greatest impact from these statutory changes.

Because every family's circumstances are different, the application of Illinois' child support guidelines remains highly fact-specific.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.