Skip to main content

Child Support Guidelines

Frequently Asked Questions

What are child support guidelines?

Child support guidelines are required by law to be used to determine the amount usually awarded for the support of minor children when parents do not reside together.

Why does the State review the child support guidelines every four years?

Federal regulations (45 C.F.R. 302.56) require that States review guidelines every four years, that the review includes an analysis of deviations from the guidelines, and that the review consider economic data on the cost of child rearing.

What is the guidelines model Illinois uses now?

Illinois uses a model called "percentage of obligor net income". This model assumes that child rearing costs will be shared between parents and assesses a percentage of the non-residential parent's net income as the support to be paid to the parent or guardian who resides with the child or children. The percentages are based on number of children that are being supported..

When was the most recent review and what was decided?

The Child Support Advisory Committee conducted the 2010 review in early December. The Committee recommended that Illinois replace the percentage of obligor income model with an income shares model.

What is the income shares model?

The income shares model for determining child support is used in 38 states throughout the US, and is the most commonly used method today. The basis for income shares is a table that uses economic data to determine the amount that parents who reside together expend for the needs of their child or children, based on combined family income and the size of the family. The method then determines the pro-rated amount each parent should contribute to their child or children when the parents do not reside together.

Why did the Illinois Child Support Advisory Committee recommend that Illinois consider replacing the percentage of obligor income model with the income shares guidelines model?

Although percentage of obligor income and income shares yield approximately the same results for most families, income shares can yield markedly different results for certain families – primarily families where the parents incomes are very different. In general, income share is considered a more equitable approach to computing child support.

Additionally, percentage of obligor income does not provide guidance about adjustments when parents each have a significant amount of parenting time – often called "shared parenting" – or when one or more children live with one parent and another child or other children live with the other parent. Income shares does offer a mechanism for shared parenting time to be included in guidelines calculations, if the parenting time meets a minimum threshold that will be established in the adoption of a new model.

Percentage of obligor income does not easily allow for consideration of families where one or both parents have unusually high or unusually low income. Income shares does offer a mechanism for consideration of these factors.

Most of all, income shares begins with an explicit understanding between parents of what is the normal cost two parents of their combined income circumstances spend to rear children, and what their relative proportion of those expenses should be. Parents begin their new parenting circumstances with facts and with the knowledge that the process is fair.

What's next?

The Child Support Advisory Committee is in the process of drafting a legislative proposal. Once a draft is completed, the Committee and HFS will seek sponsorship of the bill from a Member of the General Assembly for presentation in the Spring 2012 session. Update July 2012 : Discussions on this topic continue. A legislative draft has not yet been completed. 

The legislative proposal will include a suggested effective date. That date is likely to be some years in the future – perhaps as far out as 2014- to allow for the amount of time it will take to implement a new system and to provide the necessary education and training.

Other Information

Gross Income

Net Income

Income Basis and Income Shares Guidelines Models