Divorce brings a long list of financial questions, and few loom larger than spousal maintenance, sometimes still called alimony. Whether you expect to pay it or receive it, understanding how Illinois calculates, awards and eventually ends maintenance can help you plan for what comes next. At KHK Family Law & Divorce Attorneys, we have spent more than 70 years of combined experience guiding Chicago-area families through exactly these questions, and Attorney Matthew Katz brings a unique perspective to the table: over 20 years of family law experience paired with a Master’s in Social Work from the University of Chicago. That combination means our team looks at maintenance cases through both a legal and a human lens, understanding not just what the law allows but what a fair outcome actually looks like for a family in transition.
The Illinois Guideline Maintenance Formula
For most couples, Illinois uses a straightforward guideline formula to calculate spousal maintenance. This formula applies when the couple’s combined gross income is less than $500,000 per year, which covers the majority of divorce cases in the state. Under the guidelines, the court takes 33 and a third percent of the higher earning spouse’s net income and subtracts 25 percent of the lower earning spouse’s net income. The result is the annual maintenance amount, though the total awarded generally cannot push the receiving spouse’s income above 40 percent of the couple’s combined income.
This formula gives both spouses a reasonably predictable starting point, which is one reason so many maintenance cases settle without a lengthy trial. Still, the formula only calculates the amount, not the length of time payments will continue, which depends on a separate calculation tied to the length of the marriage.
When Courts Go Off Guidelines
Not every case fits neatly into the guideline formula, and Illinois law gives judges the flexibility to deviate from it when the standard math does not produce a fair result. A signed prenuptial or postnuptial agreement is one of the most common reasons a court sets aside the guidelines, since these agreements often spell out maintenance terms the couple agreed to in advance.
Beyond marital agreements, judges can also go off guidelines when a spouse’s physical or mental health requires a different arrangement, or when custodial responsibilities for children make the standard formula impractical. Illinois statute lists more than a dozen factors a court may weigh in these situations, including each spouse’s earning capacity, their standard of living during the marriage, and their ability to become self-supporting after the divorce. Because off-guideline cases involve more judicial discretion, they often benefit from a family law attorney who can present the full picture of a client’s circumstances persuasively.
How Long Maintenance Payments Last
Once the amount of maintenance is set, Illinois law also provides a formula to determine its duration, based directly on the number of years the couple was married. For marriages under five years, the length of maintenance is calculated at roughly 20 percent of the length of the marriage, meaning payments are typically brief. That percentage climbs steadily as the marriage gets longer, reaching roughly 40 percent of the marriage’s length for couples married between nine and ten years.
At the far end of the spectrum, marriages of 20 years or more often result in permanent or indefinite maintenance, meaning payments can continue for the recipient’s lifetime unless a future event changes the arrangement. This sliding scale reflects a basic principle in Illinois family law: the longer two people built a shared life and combined finances together, the more time the law gives the lower earning spouse to become financially independent again.
Modifying or Ending Spousal Maintenance
Maintenance orders are not necessarily set in stone once the divorce is finalized. Section 510 of the Illinois Marriage and Dissolution of Marriage Act allows either spouse to return to court and request a modification when circumstances substantially change. A significant increase or decrease in either spouse’s income is one of the most common grounds for modification, particularly if a job loss or a career change has meaningfully altered someone’s ability to pay or their need to receive support.
Maintenance can also end earlier than scheduled under certain conditions. If the spouse receiving maintenance remarries, payments typically stop. The same is often true if that spouse moves in with a new partner and the couple lives together in a way that resembles a marriage, especially if the new partner is contributing to that spouse’s financial support. Because these situations can be fact intensive and sometimes contested, working with a knowledgeable divorce attorney is often the difference between a smooth modification and a drawn out dispute.
Why Guidance Matters in Maintenance Cases
Spousal maintenance sits at the intersection of financial planning and emotional adjustment, and getting it right the first time can save both spouses years of uncertainty. Whether your case fits neatly into the guideline formula or requires the court to weigh a longer list of factors, having a clear picture of the law before you walk into a courtroom or a settlement negotiation puts you in a stronger position.
KHK Family Law & Divorce Attorneys has built its practice around exactly this kind of guidance, combining decades of courtroom experience with a genuine understanding of what families are going through. Our team includes staff fluent in both English and Spanish, including our managing partner, because clear communication matters just as much as legal skill when families are navigating one of the most difficult chapters of their lives.
If you have questions about spousal maintenance, whether you are the paying spouse or the one who may need support after divorce, our Chicago family law team is ready to walk you through your options.
