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  • Steve Rakowski

Explaining the Illinois Income Shares model

Since 2018, Illinois has used the Income Shares child support model. This article unpacks the amended Income Shares child support guidelines that took effect January 1, 2019.

A few years ago, Illinois underwent a change in how child support is determined. When parents do not live together, Illinois law still requires child support to be paid. However, since 2018, Illinois has used the Income Shares child support model. This model considers both parents’ incomes in determining the support amount.

The purpose of this article is to unpack the amended Income Shares child support guidelines effective January 1, 2019 (Pub Act 100 0923 [08/17/18]).

How Income Shares works

Income Shares uses a chart to determine the basic support obligation. The figures in the chart are based on the combined income of both parents. This model strives to approximate the amount of money the parents would spend from their combined incomes if they stayed together. In this model, one parent pays support to the other. Typically, the parent with the majority of the parenting time receives support from the other. (This is not always the case, however. For a detailed discussion on exceptions under Illinois case law, contact your attorney at LSR Family Law Group.)

First, determine percentage of net incomes

Prior to the Income Shares model, the support payor (one who pays support) had their support amount calculated based on a percentage of their net income. The new Income Shares model requires a consideration of both parents’ net incomes.

To determine net incomes, the first task is to determine whether the standardized tax amount or individualized tax amount will be applied.

The standardized tax amount is just as its name suggests: It is the amount of state and federal tax using the standard deduction and it is set out in the Gross to Net Conversion Table published from time to time by the Illinois Department of Healthcare and Family Services. It assumes the taxpayer is single with one personal exemption, with Social Security and Medicare taxes calculated at the Federal Insurance Contributions Act rate. The person who has the majority of the parenting time would also get to use dependency exemptions in calculating their net income.

The individualized tax amount is based on an individual’s calculation of net income. This method is used when one parent has a mandatory retirement contribution through an employer and other factors that deviate from the criteria for calculating the standardized tax amount. This approach can only be used if the parties agree or the court approves it.

Once net incomes are derived for each parent, they are added together. Each parent’s percentage of the combined total is calculated by dividing each parent’s net income by the combined total. For example, if Parent One earns $110,000 net income, and the combined total of both parents’ net incomes is $150,000, Parent One would pay 66.67 percent of the child support obligation. Parent Two would pay 33.33 percent.

The parent receiving support is assumed to be paying the money directly for the benefit of the child(ren). Parent Two does not actually write Parent One a check and it is not offset against Parent One’s support amount.

Next, consult the Income Shares schedule

Now that we have determined each parent’s respective support obligation, the next step in determining the actual child support amount is to refer to the Income Shares schedule based on net income. It is also published by the Illinois Department of Healthcare and Family Services. This spreadsheet lists the amount of support for the applicable number of children. The amounts were developed by taking national averages of expenditures by parents covering 290 categories of typical child expenses. These amounts have not been successfully challenged to date and you should expect that the court will use them in your case.

The amount of combined child support is identified in the spreadsheet for the applicable number of children. To determine each parent’s respective share, the amount of combined support from the spreadsheet is multiplied by the percentage of each parent’s respective obligation.

Exceptions to the Income Shares model

This model has some exceptions. The primary exception is if there is a multifamily adjustment. If one of the parents has a child from a prior relationship, the amount of that parent’s net income would be reduced by the amount of support actually paid by that parent for that child. Effectively, their percentage of the combined net monthly income would decrease and there would be a corresponding decrease in the amount of the total support obligation the parent pays for the child(ren) currently under consideration.

A second exception commonly encountered is when one parent owes a duty of spousal support to the other. In this case, the amount of the maintenance actually paid is deducted from the net income of the spouse who paid it. That same amount is added to the net income of the spouse who receives it. The percentages of the total combined incomes are calculated and multiplied by the amount of the total support obligation.

Another exception is when the parents share the physical care of the child. If each parent has at least 146 overnight parenting events per year, the basic child support obligation from the spreadsheet is multiplied by 1.5 to derive an adjusted or shared-care support amount. This is done because the law assumes actual expenses are higher because many of them are duplicated. The percentages of the parents’ respective obligations for the shared care support amount are then determined. The final step is to multiply each parent’s support obligation by the percentage of overnights the other parent has had. Each parent’s obligation is then offset against the other’s. The one with the higher obligation pays the other the difference.

Special notes about the Income Shares model

It should be noted that the passage of this new law alone does not entitle one parent to seek a review of a child support order entered under the old statute. For the court to allow an application for support review, there will first need to be a determination that other circumstances — unforeseen at the time of the original order — exist. If the initial threshold burden is met, the court will review the child support obligation, applying the new Income Shares model.

The Income Shares guideline formula is the preferred formula judges use to determine support obligations. Although the law allows a judge to deviate from the guidelines, the judge must specify the reasons for the deviation in writing. Suffice it to say, courts do not like to deviate.

Finally, it is important to note that certain child expenses are provided for separately under the new law. Day care, extracurricular activities, and school expenses are some of the most common examples. In cases where these expenses exist, the court will order the parties to share them in the same proportions their respective incomes bear to their combined joint net income.

The goal of this discussion was to help bring some clarity to the new Income Shares child support model. If you have any questions about the new law and how it applies to you, please call any of the attorneys at LSR Family Law Group. We would be happy to arrange a consultation.


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