Both parents have a legal duty to provide for their child’s basic needs. When parents of a child or multiple children, are no longer together, one or both may petition their local family court or their state child support enforcement agency to order the other to pay child support.

Child support is supposed to cover the child’s basic necessities and must be reasonable expenses. Child support expenses can include the following:

  • Housing;
  • Food;
  • Clothing and shoes;
  • Medical Care; 
    • Including payment of any medical premiums if the family does not qualify for medicaid; and 
    • Payments for any ongoing medical conditions such as prescriptions or equipment.
  • Childcare including daycare and after school programs;
  • Educational expenses such as books, backpack, pencils, etc.;
  • Transportation; and/or
  • Extracurricular activities including summer camps may also be considered.

Have there Been Any Changes to the State of Illinois Child Support Determinations?

Yes, in 2017 the state of Illinois made some changes to the method or formula that the court system uses to determine a parent’s child support obligation. The major change that occurred involved the use of the recipient parent’s net income.

Prior to the change, the courts calculated child support based on the paying parent’s net income and number of children the paying parent is responsible for. The reformed Illinois law now favors a shared incomes model in which both parents’ net income is considered in the formula.

This approach was intended to make child support determinations more equitable or fair rather than only looking at one parent’s income and responsibility.

How Do I Calculate My Child Support Obligation Based on the Current Method?

Due to the change in method, there are different factors that determine your child support obligation:

  1. Determine the net income of each parent;
  2. Combine the net incomes of the parents;
  3. Use the income shares table (available on the Illinois state government site) to determine both parents basic child support obligation. The table provides amounts for up to six children;
  4. Add any additional or special expenses for that particular child. For example, a child with a disability may have more expenses than what is included in the basic child support table;
  5. Once you have the total monthly support obligation for both parents, determine the amount owed by each parent. Each parent will be responsible for an amount proportionate to their net income; parents who make more than the other will owe more; and
  6. Finally, take into consideration the amount of time each parent spends with the child; usually defined as how many nights a year the child spends with that parent. Shared parenting is typically an equal number of nights and situations where the child spends more nights with one parent will increase the amount owed by the one who spends less time.

What are the Expenses I can Deduct to Determine My Net Income for Child Support in Illinois?

Net income is the income you have after qualifying deductions. For child support, a parent can usually deduct the following expenses from their total or gross income to reach their net income:

  • Federal income tax;
  • State income tax;
  • Social security withholdings or payments;
  • Mandatory retirement contributions: ones that are required by an employer or by law. Voluntary contributions are not considered;
  • Health insurance premiums for yourself and all dependents;
  • Prior or other court ordered child and spousal support obligations that were actually paid; and/or
  • Other expenditures that are required to generate income.

Is there a Calculator that Can Help Me Estimate My Child Support Obligation?

Yes. The state of Illinois offers a free online calculator to provide an estimated child support amount. However, if you or the other parent has any unusual expenses or your child has particular needs, the calculator may not be as accurate.

The calculator uses what is typical for a standard family. Deviations from the standard child support may apply in your case if you have a special situation.

Do the Changes to the Child Support Calculation Automatically Change My Old Order?

No; the existence of the new method of calculation does not automatically change child support orders issued before the new legislation. Just as before, any parent wishing to increase or decrease a child support order needs to file a motion to modify their child support obligation.

It is important to continue to make current payments timely until a court has modified the order. Modifications of child support have always been and will continue to be based on a substantial change in circumstances such as a remarriage, increase in the parent’s income, or a new and substantial need of the child. However, if the new guidelines substantially change the child support obligation that may be enough to secure a modification.

Should I Consult a Lawyer About Calculating My Child Support in Illinois?

A local family lawyer can be helpful in determining your exact child support obligation. They can also explain what modification factors are most important in your local court. Having a lawyer represent you in a child support matter can help secure a fair child support order.