Parenting schedules can play a major role in child support cases in Illinois. For many families, the number of overnight visits each parent has with a child may directly affect how support is calculated.

Now, a proposed Illinois bill known as SB3524 could significantly change the way child support works in shared parenting situations.

Currently, many parents and family law attorneys closely monitor whether a parent reaches a specific threshold of overnight parenting time. Under the proposed legislation, support calculations could begin adjusting earlier and more gradually than they do under current law.

For parents navigating divorce, custody disputes, or parenting agreements, understanding these possible changes may become increasingly important.

What Is the 146 Overnight Rule in Illinois?

Many parents refer to the current system as the “146 overnight rule.”

Under existing Illinois child support guidelines, a shared parenting formula may apply when each parent has the child for at least 146 overnights per year. This threshold is important because it can substantially change how child support is calculated.

In many cases, parents who fall just below the 146-night mark may see very different financial outcomes compared to parents who exceed it, even if the actual parenting schedule is relatively similar.

Because of this, overnight counts often become a major issue during:

• custody negotiations
• parenting time disputes
• divorce settlements
• child support modification cases

Courts may examine parenting schedules carefully when determining whether shared parenting calculations apply.

What Would SB3524 Change?

SB3524 proposes a more gradual approach to calculating child support in shared parenting cases.

Instead of relying heavily on a single threshold at 146 overnights, the proposed law would introduce adjustments beginning at approximately 110 overnights per year.

The bill would also create gradual percentage adjustments between 110 and 145 overnights rather than triggering one major calculation change at a single point.

In practical terms, this could reduce the sharp financial difference that currently exists between:

• parents with slightly different parenting schedules
• shared parenting arrangements near the current threshold
• cases involving flexible custody schedules

The proposal may also include the use of overnight equivalents in certain situations, which could affect how parenting time is evaluated for support purposes.



Supporters of the bill argue that the current system can create unnecessary conflict over overnight counts, while the proposed structure may better reflect modern co-parenting arrangements.

Why This Matters for Parents

If SB3524 becomes law, it could affect many areas of family law cases in Illinois.

For example, parents negotiating custody agreements may need to consider how parenting schedules could influence child support obligations under the updated formula. The proposed changes could also impact:

• shared parenting negotiations
• financial planning after divorce
• parenting time agreements
• child support modification requests
• co-parenting disputes

In some situations, parents may place significant focus on overnight schedules because even small changes in parenting time may affect support calculations.

For families already navigating emotionally difficult custody matters, these financial considerations may add another layer of complexity.



Speaking with a child support attorney in Illinois may help parents better understand how proposed legal changes could apply to their situation.

Could Parenting Time Affect Child Support?

Yes. Parenting time can significantly affect child support calculations in Illinois.

Courts often examine the number of overnights each parent has with the child, along with the overall parenting arrangement, when determining support obligations. However, every case is different. Factors such as:

• each parent’s income
• the parenting schedule
• childcare costs
• healthcare expenses
• educational expenses
• may also influence the final calculation.



Because child support laws can be complex and subject to legislative updates, parents should avoid assuming that one formula automatically applies to every case.

Is SB3524 Already Law?

At this time, SB3524 has passed both houses of the Illinois legislature, but families should continue monitoring updates before assuming the changes are final.

Legislation can still move through additional procedural steps before becoming fully effective law.

Parents involved in ongoing divorce, custody, or child support matters may benefit from staying informed about potential legal developments and how they could affect future support calculations.

Child support and parenting time issues can become complicated, especially when laws and calculation methods continue evolving.



If you have questions about child support, custody agreements, or shared parenting arrangements in Illinois, the family law team at Weiss Ortiz Attorneys & Mediators can help you better understand your legal options.