Illinois Child Support?

Assuming a substantial change in circumstances the income shares will apply. There is a slightly different calculation if there are 146 or more over-nights per year. That would include vacation time. As to what constitutes a substantial change in circumstances, every case is unique. A change in salary that would move support in a significant amount up or down would qualify. However, if the only reason is a change in the law, that does not qualify. You would benefit by an in-person consultation with an experienced family law attorney with all your documents including his motion for review and specific advice. If your ex has provided his Financial Affidavit and supporting documents, that will help an attorney run the numbers to see if there is a substantial change and what that would mean to the amount you would be receiving under the new statute.

If no substantial change has occurred, then there is no modification of the prior support order.If there has been a substantial change, support is then calculated using the income shares method regardless of the number of nights he has. No case defines what a substantial change is, and that decision is based upon the discretion of the judge.

an income change of 6% or more would be substantial based on a recent appellate court case that says a 6% increase in parenting time is substantial.
if he does not have 146 nites, then the shared parenting sheets are not used.
i have the same issue pending in waukegan. the father got a 7k increase in pay. we did a motion to modify his support. due to income shares, it will go down. hearing at end of october.