In Illinois, child support follows an “income shares” model rather than the old percentage-based system. Previously, child support was calculated as a percentage of the paying parent’s net income (e.g., 20% for one child, 28% for two children). However, under the new system, both parents’ incomes are considered, as well as the number of overnights each parent has with the child per year.

To qualify for shared parenting time, the non-custodial parent must have at least 146 overnights per year. This number was set by the legislature and is not equivalent to 50% of the year but serves as a threshold for reducing child support obligations. If the paying parent has fewer than 146 overnights, their child support payments remain the same. However, once they reach 146 overnights, the obligation begins to decrease, reflecting the increased time spent with the child. For every additional overnight beyond 146, the support obligation continues to decrease up to a 50/50 split, which corresponds to 182-183 overnights.

In cases where both parents share equal parenting time (50/50), the child support payment may be minimal or even non-existent, depending on the relative incomes of the parents. However, if there is a significant income disparity, such as one parent earning $300,000 annually while the other is a stay-at-home parent, the higher-earning parent may still be required to pay child support even with equal parenting time. This ensures that the child’s standard of living is maintained regardless of the income differences between the parents.