With the passage of income shares legislation (Pub. Act 100-15), Illinois law regarding child support dramatically changed. Prior to the passage of the income shares legislation, Illinois had comprehensive changed to its family laws in virtually all areas other than child support. This is because there was a separate committee established to review and update the child support guidelines from the so called “Family Law Study Committee.” This later committee was the one that was responsible for the 2016 comprehensive re-write of Illinois statutory law. And as of 2012-2013 there are working on their quadrennial review (albeit a few years late due to Covid).
Through to July 1, 2017, Illinois used a child support system based solely on a guideline percentage and the net income of the non-residential parent. This resulted in the same guideline support regardless of the division of parenting time, the respective incomes of the parties, and other factors. With Public Act 100-15, Illinois adopted an income-share approach that uses a mathematical formula to consider parenting time and both parents’ incomes. Accordingly, “income shares” is the model in use in 41 states. In considering the income of both parents in determining child support, the income shares approach has each parent is responsible for their pro-rated share.
The income shares model has a critical impact on prospective cases where parenting time is shared. This is due to the definition of “shared parenting” and the calculation of a cross-credit used by the income sharing models. Illinois’ income sharing legislation defines “shared parenting” as a parent having overnight parenting time for at least a certain number of overnights per year. The law defines shared-parenting time as exercising 146 nights per year. This number represents 40% of the overnights.
Under Illinois income shares model both parents contribute to the expenses of the children in addition to the basic child support obligation. Calculation of child support for each parent then assumes that each parent is the non-residential parent and the other parent is the residential parent. A 50% multiplier is applied to the basic obligation to account for the duplicated child-rearing costs between the parents’ households. Such items would include housing and transportation. Each parent’s share of the basic obligation is cross-multiplied with the percentage of time the other parent has parenting time on an overnight basis with the child.
We can potentially expect significant tweaks to our income-shares statute in the 2023 or 2024 legislative session due to the review that is underway and supposed to occur every four years.