1 Child
Not published
of income
Data updated May 2026
2024 guideline data Income Shares model OCSE FY2023 source
Illinois Child Support Guidelines
Illinois runs the Income Shares model, with no statutory income cap and a parenting-time credit - see the base percentages and OCSE FY2023 enforcement figures below.
By PlainChildSupport Editorial · · Source: Illinois Revised Statutes · Last updated: 2024
Income Shares
2 Children
Not published
of income
3 Children
Not published
of income
4 Children
Not published
of income
Income Cap
None
uncapped
Child Support Snapshot: Illinois
Illinois operates under the Income Shares model, one of 43 U.S. states using this framework. Illinois's published guideline schedule is being updated on this site to reflect its current formula, check the official Illinois calculator or guidelines below for exact figures. Unlike capped states, there is no statutory income ceiling, the formula applies to the full reported income before deductions. Median household income here runs $72,205/yr.
Illinois ranks #37 of 51 reporting states on OCSE collection efficiency and #8 by caseload volume, see the case counts, collection rate, and paternity-establishment figures in the enforcement breakdown below.
Illinois allows a parenting time adjustment, which can materially reduce the base obligation when the non-custodial parent exercises substantial overnight time. A percentage figure alone doesn't determine the dollar amount, see how Illinois compares to other guideline models →
How Illinois Calculates Child Support
Illinois uses the Income Shares model. Both parents' incomes are combined, the total obligation is looked up from a schedule, then split proportionally based on each parent's income share.
Illinois moved from Percentage of Income to the Income Shares model effective July 1, 2017 (Public Act 99-0764, 750 ILCS 5/505). The prior flat-percentage schedule shown on this site was the pre-2017 repealed model; the interactive calculator is disabled pending correct Income Shares schedule data.
Guideline Details
| Parameter | Value |
|---|---|
| Formula Model | Income Shares |
| Income Floor | None |
| Income Ceiling | Uncapped |
| Parenting Time Adjustment | Available |
| Median Household Income | $72,205/yr |
| Single-Child Base | % (rank #51 of 51) |
Disclaimer: This page provides estimates for informational purposes only. Actual child support amounts may differ based on judicial discretion, deviation factors, and current Illinois guidelines. Consult a family law attorney in Illinois for legal advice.
Illinois Child Support Enforcement
524,000
Active Cases
$1,100M
Annual Collections
57.6%
Collection Rate
73.1%
Cases with Orders
94.7%
Paternity Established
Illinois vs national average (51 reporting states)
Collection rate 57.6%
national
57.6% of assessed support collected; national average 60.6%.
Paternity established 94.7%
national
94.7% of cases have legal parentage established; national average 94.9%.
Cases with orders 73.1%
73.1% of the caseload has a formal child support order in place.
Source: OCSE FY2023 preliminary report OCSE FY2023 preliminary report
Interactive Calculator for Illinois
The Illinois interactive calculator is being finalized. Use the official state calculator below for your estimate.
Official IL CalculatorOther Income Shares States
Frequently Asked Questions
Does parenting time affect child support in Illinois?
Yes. Illinois provides a parenting time adjustment when the non-custodial parent exercises significant overnight time (typically 40% or more). This credit reduces the base child support obligation proportionally.
Every figure on PlainChildSupport is rendered directly from official state guidelines and federal enforcement data, no number is typed in by an editor. This page draws directly on official state guidelines and federal enforcement data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.
Read our methodology - how this data is sourced, computed, and verified.
Data sources
Data sourced from official federal and state child-support agency records (NCSL, state statutes, ACS). See our methodology for details. Retrieved and formatted by PlainChildSupport Editorial
