Illinois Child Support Changes in 2027: The New 110-Overnight Rule Explained
Illinois child support guidelines are changing in 2027, and one of the most important changes involves how parenting time affects child support.
Beginning January 1, 2027, Illinois will lower the threshold for applying its shared-care child support calculation from 146 overnights per year to 110 overnights per year.
For parents going through divorce or separation, this is a significant change. Parenting schedules that do not qualify for shared-care treatment under the current guidelines may be treated differently beginning in 2027.
For parents using divorce mediation, however, there is an equally important consideration: parenting time should first be based on what works for your children and your family and not on reaching a particular child support threshold.
At the Center for Divorce Resolution, we help parents understand how parenting decisions and financial decisions interact so they can have informed, productive conversations and work toward agreements that make sense for their family.
How Is Child Support Calculated in Illinois?
Illinois uses an Income Shares model for determining child support.
Rather than looking only at the income of the parent paying support, the calculation generally considers the incomes of both parents, the number of children and each parent's proportionate share of the parents' combined income.
Other factors may also be part of the calculation, including:
Parenting time
Health insurance for the children
Childcare expenses
Certain child-related expenses
Other applicable financial adjustments
The Illinois Department of Healthcare and Family Services publishes the Schedule of Basic Child Support Obligations and related income tables used in calculating support.
The Current 146-Overnight Rule
Under the guidelines in effect during 2026, the special shared physical care calculation generally applies when each parent has at least 146 overnights with the child each year.
That's approximately 40% of the year.
This can make the 146th overnight financially significant. In some divorces, parents may become focused on whether a schedule provides 145 or 146 overnights because crossing that threshold can affect the child support calculation.
Beginning in 2027, that threshold changes substantially.
The New 110-Overnight Rule for 2027
Effective January 1, 2027, Illinois lowers the shared physical care threshold from 146 to 110 overnights per year, or approximately 30% of the year.
As a result, parenting schedules involving 110, 120, 130 or 140 overnights may receive shared-care treatment even though they do not meet the current 146-overnight threshold.
However, reaching 110 overnights does not mean that a parent automatically receives the same child support treatment as a parent with 146 or more overnights.
Instead, the new law creates a graduated adjustment between 110 and 145 overnights.
The 2027 Parenting-Time Adjustment
The new guidelines establish the following adjustment ranges:
The 2027 Parenting-Time Adjustment
The new guidelines establish the following adjustment ranges:
Annual Overnights Adjustment
110–114 10%
115–119 9%
120–124 8%
125–129 7%
130–134 6%
135–139 4%
140–145 2%
146 or more No additional adjustment
These percentages are part of the shared-care formula. They should not be interpreted as simply reducing child support by 10%, 8%, 6% or another percentage.
The actual child support amount depends on the parents' incomes, number of children, parenting schedule and other applicable financial information.
Why Is Illinois Making This Change?
One practical effect of the current guidelines is the financial significance of the 146th overnight.
A parent with 145 overnights does not currently satisfy the shared-care threshold, while a parent with 146 does.
The new approach begins recognizing substantial parenting time at 110 overnights and gradually adjusts the calculation as parenting time approaches 146 overnights.
From a mediation perspective, this is important because parenting arrangements do not always fit neatly into an all-or-nothing formula.
A family with a child spending approximately one-third of the year in one parent's home may have very different financial circumstances from a family in which the child sees that parent only occasionally.
The new guidelines attempt to recognize that distinction.
Parenting Time Should Be About Your Children—Not Child Support
The new 110-overnight threshold creates an important conversation for parents in mediation.
Parents understandably want to know how a proposed parenting schedule will affect child support. Understanding the financial consequences of different options is part of making an informed decision.
But a parenting schedule should not be designed simply to reach a particular child support threshold.
Instead, parents should first consider questions such as:
What schedule works best for our children?
How old are the children and what are their developmental needs?
What are their school and extracurricular schedules?
What are each parent's work responsibilities?
How will transportation between households work?
How far apart will the parents live?
What schedule can both parents realistically maintain?
How can the children maintain meaningful relationships with both parents?
Once parents develop a parenting arrangement that works for their family, they can then understand how that arrangement affects the child support calculation.
This is one of the areas where divorce mediation can be particularly valuable. Parenting and finances do not have to be discussed in isolation.
What Are "Overnight Equivalents"?
The 2027 changes also recognize the concept of overnight equivalents.
Not every family's parenting arrangement is accurately reflected simply by counting where a child sleeps.
A parent might, for example, regularly care for a child for substantial periods during the day or evening, while the child ultimately sleeps at the other parent's home.
The new provisions allow certain significant periods of parenting time on separate days to potentially be recognized as overnight equivalents under the circumstances provided by the guidelines.
This may be particularly relevant for parents with nontraditional work schedules, including healthcare professionals, first responders, restaurant workers, shift workers and others whose schedules do not easily fit a conventional overnight parenting arrangement.
In mediation, parents can identify these caregiving responsibilities and discuss whether their parenting plan accurately reflects the way they actually care for their children.
When questions arise regarding how the law applies to a particular family's circumstances, each parent may obtain advice from independent legal counsel.
Does 50/50 Parenting Time Mean No Child Support?
Not necessarily.
This is a common misunderstanding about Illinois child support.
Equal parenting time does not automatically result in zero child support because Illinois considers both parenting time and income.
If one parent earns substantially more than the other, there may still be a child support obligation even when the parents have equal or nearly equal parenting time.
This is why it can be helpful during mediation to look beyond a single child support number and consider the family's entire financial picture.
Who pays for health insurance? What about childcare? Activities? School expenses? How different are the parents' incomes? What will it cost to maintain two households for the children?
Those conversations can be just as important as the guideline calculation itself.
What If We Are Mediating Our Divorce in 2026?
Parents going through mediation during 2026 are in an unusual position because the new provisions take effect on January 1, 2027.
If your proposed parenting schedule falls between 110 and 145 overnights, it may be useful to understand both the guidelines currently in effect and the changes coming in 2027.
That does not mean parents should redesign their parenting schedule to obtain a particular financial result.
Instead, understanding the upcoming change allows both parents to ask better questions, consider the financial implications of their decisions and identify issues they may want to discuss with their independent attorneys before finalizing an agreement.
What If We Already Have a Child Support Order?
Parents with existing child support orders should not assume that the January 2027 changes will automatically recalculate their child support.
Existing child support orders and potential modifications involve additional considerations.
If parents believe that changes in parenting arrangements, income or other circumstances justify revisiting support, mediation may provide an opportunity to exchange updated information and discuss whether they can reach an agreement.
The mediator does not determine whether either parent has a legal right to a modification. Each parent may consult independent legal counsel regarding their rights and obligations.
A Better Conversation About Child Support
Child support can become one of the most stressful financial conversations in a divorce.
It is often easier to discuss when both parents understand how the calculation works, have access to the same financial information and can evaluate options together.
At the Center for Divorce Resolution, our role is not to advocate for one parent against the other.
We provide a neutral environment where parents can organize financial information, understand child support calculations, evaluate different scenarios and discuss how parenting time and child support fit into their broader divorce settlement.
The goal is not for one parent to "win" the child support calculation.
The goal is for both parents to understand the numbers, understand their options and work toward an agreement that supports their children while allowing both households to move forward.
Considering Divorce Mediation in Illinois?
If you are considering divorce, currently going through a divorce, or need help addressing post-divorce parenting or financial issues, the Center for Divorce Resolution can help.
Our mediation process provides a private, structured and neutral environment where both parties can work through parenting, child support, property division and other financial issues together.
We focus on education, financial transparency and constructive communication, helping both parties understand the issues and evaluate options before making decisions.
If you have questions about how the 2027 Illinois child support changes may affect the financial discussions in your divorce, contact the Center for Divorce Resolution to learn more about the mediation process and schedule an initial consultation.
This article is provided for general educational and informational purposes only and is not legal advice. The Center for Divorce Resolution serves as a neutral mediation resource and does not represent either party or provide either party with legal advice. Child support calculations and the legal requirements for establishing or modifying support depend on the circumstances of each family. Parties are encouraged to consult independent legal counsel regarding their individual legal rights and obligations.