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Calculating Spousal Maintenance (Alimony) in Illinois

Until January 2015, judges in Illinois calculated maintenance (formerly known as alimony) without using a formula and instead relying on a list of factors that appeared in the statute and in relevant case law from the appellate and supreme courts. On January 2015, a new law became effective in Illinois and implemented a formula (which has since been amended effective January 1, 2018).

The first step is for a judge to determine whether maintenance is appropriate. Under the current formula, once a judge has determined that maintenance should be awarded, a maintenance award should equal 30 percent of the payor's gross income minus 20 percent of the payee's gross income, but in no event more than 40 percent of the parties' combined income. An example is as follows:

Assume the husband makes $100,000 per year and his wife earns $50,000 per year. Thirty percent of $100,000 is $30,000, and 20% of $50,000 is $10,000. Subtract $10,000 from $30,000 and for the resulting conclusion that the husband owes the wife $20,000 per year (or $1,666 per month) in maintenance.

But this is not the end of the formula because that $20,000 per year payment would push the wife's annual gross income over the 40 percent of combined income limit. This is because adding their combined incomes amounts to $150,000, 40% of which is $60,000. Under the first step, the wife would be receiving $70,000 per year total. Accordingly, the 40 percent rule caps the wife's maintenance at $10,000 per year.

A separate formula determines the length of maintenance based upon the length of the marriage, calculated from the date of marriage through he date that one party files a petition for dissolution of marriage in court. For example, a marriage that lasted five years, the maintenance award would last for 20 percent of that span, or one year. The percentage is then increased by 4 percent for every year beyond 5 years through the 20th year of marriage. For example, the length of maintenance for a marriage between 5 and 6 years is 24 percent, between 6 and 7 years is 28 percent and so on. For marriages that last longer than 20 years the Court may award maintenance for a time either equal to the length of the marriage or for an indefinite period of time (sometimes called "permanent maintenance").

The purpose of the new approach using a formula is because maintenance awards had become very inconsistent among different counties and even judges within the same county. Two cases with very similar facts could end up with extraordinarily different results depending on the judge assigned to the case. The new statute does allow a judge to deviate from the formula if the specific facts of the lead the judge to believe that it would be unfair to apply the formula in that case.

There are additional intricacies of the law that must be considered in every case to determine the likely result of maintenance in each specific case. If you would like more information, please feel free to contact me by phone at (312) 884-1529 or by email at

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