With the passage of income shares legislation (Pub. Act 100-15), Illinois law regarding child support dramatically changed. Prior to our July 1, 2017 effective date of the income shares law, Illinois had comprehensive changed to its family laws in all other areas. This is because the legislature created a separate committee to to review and update the child support guidelines. This became known as; the “Family Law Study Committee.” This committee was responsible for the 2016 comprehensive re-write of Illinois statutory law. And as of 2012-2023, the committee finalized 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. The Illinois income sharing law uses a mathematical formula that considers parenting time and both parents’ incomes. Accordingly, “income shares” is the model in use in 41 states.
The income shares model critically impacts cases involving shared parenting time. The law defines “shared parenting” as a parent having overnight parenting time for at least a 146 overnights 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. Shared physical care 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. (These items 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 have seen that with the 2023 charts, which were adopted in February, support awards have increased depending upon the income level in the households. See page 80 of 257 for a chart that shows the average and median change for combined monthly incomes at different monthly income levels: under $90,000 per year; above this figure but under $180,000 per year; and above this figure but below the income cap of $300,000 per year. The summary indicates that:
- For the lowest income range, the average increase is modest: 5 percent to 6 percent depending on the number of children.
- The average increase is more for the middle-income range: 6 percent to 11 percent, depending on the number of children.
- The average increase is significantly more for the highest income range: 17 percent to 22 percent, depending on the number of children.