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Illinois Income Share Model: How to Calculate Child Support as of July 1, 2017

 Posted on June 20, 2017 in Family Law

llinois Income Share Model: How to Calculate Child Support as of July 1, 2017

On July 1, 2017, the Illinois Income Share Model will go into effect and substantially change the way we calculate child support today. Up until July 1, 2017, only the net income of the non-majority parent (or non-custodial parent) is used to calculate child support. Currently, net income is defined as total of all income from all sources minus various deductions such as Federal income tax, State income tax, Social Security, mandatory retirement contributions, union dues, health insurance premiums and court ordered obligations. Once a parent’s net income is calculated, the non-custodial parent pays a percentage of his net income as for child support depending upon the amount of children he or she must support (one child=20%; two children=28%; three children=28%; four children=40%). The new income share model will still rely upon a determination of a parent’s net income; however, the definition of net income will be modified. Moreover, the new model will also consider the income of both parents in determining what share of child support each parent must pay. Moreover, the new law has developed two separate charts: 1) to calculate a parent’s net income and 2) to calculate the amount of child support required for a child (or children) based upon the total combined net income of both parents. Click below to see charts.

Gross to Net Income Conversion Table

Income Shares Schedule Based on Net Income

Per the new statute, net income can be calculated two ways: 1) a parent’s gross income minus a standardized tax amount or 2) a parent’s gross income minus an individualized tax amount. A standardized tax amount is defined as the total of federal and state income taxes for a single person claiming a standard tax deduction, one personal exemption, and (if applicable), child dependency exemptions, Social Security tax and Medicaid tax. An individualized tax amount shall apply when a parent has mandatory retirement contributions in lieu of social security or potential itemized deductions such as other dependent children. It is very important to determine what kind of net income method a parent must use as the method will determine what step the parent is to follow next in calculating child support.

If a given parent falls under the standardized deduction method, that parent will then use the “Gross to net Income Conversion Table Using Standardized Tax amounts” (chart 1) created by the Department of Healthcare and Family Services to determine that parent’s net income. The parent will have to know his or her gross income and whether the parent is a majority or non-majority parent. Assuming both parents are not equally sharing parenting time, the parents may then turn to Chart 1 where the parents will find his or her gross income on the chart under “Monthly Gross Income.” The non-majority parent will use the number under the column “Parent with Duty to Support Children” that which represents his or her net income. The majority parent will use the number under the column indicating the amount of children that is shared between the parents, and that number shall represent the majority parent’s net income.

However, if a given parent does not fall under the standardized deduction method, he or she will skip Chart 1 and the parent will have to individually determine his or her net income as follows: by agreement with other parent; via a summary hearing before a judge or via an evidentiary hearing before a judge. There are provisions in the statute that provide additional deductions such as other children with other parents; however, we will explore that topic on a later date.

Once the net income of both parents is determined, the net incomes are combined to determine the total amount of child support required via the “Income Shares Schedule Based on Net Income” (chart 2). The number obtained from the chart is not the child support that a non-majority parent must pay; rather, it is the total amount of child support that should be paid towards the total support of a child (or children).

To determine the amount of child support that each parent must pay, the parents must determine what percentage they hold of the total available combined net income. Based upon each parent’s individual percentage, they shall be responsible to pay that percentage of the number acquired from chart 2; and that is the base child support for each parent. With that said, as the majority parent has the child for most of the time, he or she will not pay child support to the non-majority parent; but the non-majority parent will pay his share to the majority parent.

To illustrate the above mentioned general child support calculation, let’s assume that both parents have standardized deductions; Parent A (majority parent) makes $1000.00 gross per month and Parent B (non-majority parent) makes $3500.00 gross per month and the Parties have one child who requires a $100.00 per month health insurance premium. Per chart 1, Parent A’s net income is $900 and Parent B’s net income is $2,752; hence, total combined available net income is $3,652.00 from which Parent A holds 24.64% of the net income and Parent B holds 75.36% of the net income. Next, per chart 2, under the available net income of $3,652.00, the total child support required for one child is $780.00 per month. Moreover, add cost of insurance in the amount of $100.00 per month for total child support obligation of $880.00. Parent A will be responsible for 24.64% of $880.00 per month ($216.87) and Parent B will be responsible for 75.36% of $880.00 per month ($563.13). Hence, Parent B will pay $563.13 to Parent A.

Gross to Net Income Conversion Table

Income Shares Schedule Based on Net Income

The new income shares model and statute has much to provide and this article has only scratched the surface. On a later date, we will explore how to calculate child support if both parents have close to equal parenting time. In the meantime, if you have questions, the attorneys at Serrano Hanson can aid you in accurately calculating your share of child support and discuss what other provisions are available through the statute. Schedule a consultation today by calling Serrano Hanson at 630-844-8781. We are happy to assist our clients for matters arising in Kane, Dekalb, DuPage and Kendall County.


  • http://www.ilga.gov/legislation/publicacts/99/PDF/099-0764.pdf
  • http://www.ilga.gov/legislation/ilcs/ilcs5.asp?ActID=2086&ChapterID=59

Disclaimer: This article/blog was written by an attorney from Serrano Hanson and is accurate and true to the best of our knowledge, but there may be omissions, errors or mistakes. This article/blog (or the reading of this article/blog) does not create an attorney-client relationship, and the attorneys at Serrano Hanson do not represent the readers of this blog. The legal information contained within this blog/article is meant solely for informational purposes and is not meant to be legal advice nor a legal assessment of an individual person’s case matter; hence, you should consult with an attorney before you rely on this information

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