Here’s a look at how Illinois’ current child support formula — the percentage of income model — is calculated compared with the proposed new formula — the income shares model. In both cases, the support payment determined by the formula could be altered by a judge.
Percentage of Income
Example: Noncustodial parent has three children to support and a net (after-tax) income of $3,000 per month. Custodial parent’s income is $2,000 per month.
Only the noncustodial parent’s income is considered in the formula.
A minimum flat percentage of the noncustodial parent’s income is devoted to child support (20 percent for 1 child, 28 percent for two children, 32 percent for three children, 40 percent for four children, 45 percent for five children and 50 percent for six or more children).
In this example, the noncustodial parent pays 32 percent of net income for the three children, or $960 per month.
Income shares
Example*: Noncustodial parent has one child to support and gross (pre-tax) income is $10,416 per month. Custodial parent’s income is $4,166 per month.
The parents’ total monthly income, $14,582, is compared with an economic table that includes expected costs to raise children based on families that make the same income and remain intact.
In this example, the total child support obligation from the economic table is $2,621 per month.
The noncustodial parent’s income is 71.4 percent of the parents’ total income while the custodial parent’s income is 28.6 percent.
Therefore in this example, the noncustodial parent would pay $1,872 per month in support, or 71.4 percent of the total obligation of the parents.
*Based on other states with income shares. Illinois’ formula may vary.
Source: Illinois Division of Child Support Services
