Estimate monthly child support payments in Illinois using the state's Income Shares formula. Updated for 2026 guidelines.
Switched to income-shares model in 2017. Uses both parents' net incomes. Shared parenting adjustment when each parent has 146+ overnights.
| Children | Percentage of Combined Income |
|---|---|
| 1 Child | 20% |
| 2 Children | 28% |
| 3 Children | 32% |
| 4 Children | 36% |
| 5+ Children | 40% |
In Illinois, if a parent is voluntarily unemployed or underemployed, the court may impute income based on the parent's earning capacity, work history, education, and local job market conditions. Under the income-shares model, both parents' incomes are considered to determine the total child support obligation.
The Illinois child support enforcement agency handles establishing, modifying, and enforcing child support orders. They can assist with locating non-custodial parents, establishing paternity, and collecting past-due support through wage garnishment, tax intercepts, and other enforcement tools.
Illinois Child Support Enforcement Agency →
See how Illinois's child support guidelines compare with neighboring states.
| State | Model | 1 Child | 2 Children | 3 Children |
|---|---|---|---|---|
| Illinois | Income Shares | 20% | 28% | 32% |
| Wisconsin | Percentage | 17% | 25% | 29% |
| Iowa | Income Shares | 21% | 31% | 37% |
| Missouri | Income Shares | 21% | 31% | 37% |
| Kentucky | Income Shares | 20% | 31% | 36% |
| Indiana | Income Shares | 20% | 30% | 36% |
Get accurate child support calculations and protect your rights under Illinois law.
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