How Illinois Calculates Spousal Maintenance

Illinois uses the term “maintenance” rather than “alimony” or “spousal support.” Unlike many states that leave the amount and duration entirely to judicial discretion, Illinois provides a specific guideline formula for calculating both the amount and duration of maintenance in most cases. The governing statute is 750 ILCS 5/504, and understanding how it works is essential for anyone going through a divorce in Illinois.

This article explains the guideline formula, when courts deviate from it, how duration is calculated, the difference between reviewable and non-reviewable maintenance, and the tax implications under current federal law.

When Maintenance Is Awarded

Before calculating an amount, the court must first determine whether maintenance is appropriate. Under 750 ILCS 5/504(a), the court considers 14 factors, including:

• The income and property of each spouse, including marital property apportioned in the divorce
• The needs of each party
• The realistic present and future earning capacity of each party
• Any impairment of earning capacity due to devoting time to domestic duties or delaying education, training, or employment during the marriage
• The time necessary for the requesting spouse to acquire education, training, or employment
• The standard of living established during the marriage
• The duration of the marriage
• The age and physical and emotional condition of both parties
• Any valid agreement between the parties (such as a prenuptial agreement)
• Tax consequences of the property division on each party’s economic circumstances

The court does not need to find that the requesting spouse is destitute or unable to work. The question is whether, after considering these factors, a maintenance award is appropriate to address a significant income disparity or to help the lower-earning spouse transition to self-sufficiency.

The Guideline Formula for Amount

When the combined gross income of both spouses is less than $500,000 per year and the payor has no obligation to pay child support or maintenance from a prior relationship, the court applies the guideline formula under 750 ILCS 5/504(b-1):

Maintenance Amount = (33.33% of the payor’s net income) minus (25% of the payee’s net income)

The result is subject to a cap: the maintenance amount, when added to the payee’s net income, cannot exceed 40% of the combined net income of both parties.

Example: Assume the payor has a net income of $120,000 per year and the payee has a net income of $40,000 per year. The combined net income is $160,000.

• 33.33% of $120,000 = $39,996
• 25% of $40,000 = $10,000
• Guideline amount = $39,996 - $10,000 = $29,996 per year

Now apply the cap: the payee’s total income with maintenance would be $40,000 + $29,996 = $69,996. Forty percent of the combined net income is $64,000. Because $69,996 exceeds $64,000, the cap applies, and the maintenance amount is reduced to $24,000 per year ($64,000 minus $40,000).

The formula uses net income, which is defined under the statute as gross income minus certain deductions, including federal and state income taxes, Social Security contributions, and mandatory retirement contributions.

Duration Multipliers

The duration of guideline maintenance is determined by multiplying the length of the marriage by a statutory multiplier. Under 750 ILCS 5/504(b-1)(1), the multipliers are:

Example: For a 12-year marriage, the multiplier is 0.52. Duration = 12 years x 0.52 = 6.24 years of maintenance.

For marriages of 20 years or longer, the court may order maintenance for a period equal to the length of the marriage or for an indefinite term. There is no automatic right to permanent maintenance, but it becomes significantly more likely with long marriages, particularly when the receiving spouse has limited earning capacity.

Deviation from the Guidelines

The guideline formula is not mandatory. The court may deviate from the guideline amount or duration based on any relevant factors, including:

• The age and health of the parties. A spouse with serious health limitations may need more or longer maintenance.
• The property division. If the lower-earning spouse received a disproportionately large share of marital property, the court may reduce maintenance. Conversely, if the property division was insufficient, maintenance may be increased.
• Career sacrifices. A spouse who left a career to raise children for 15 years faces a different situation than one who worked throughout the marriage.
• The needs of the children. If the custodial parent’s expenses are elevated due to caring for children with special needs, that can affect the maintenance calculation.
• The earning capacity of both parties. If one spouse has a professional degree or license obtained during the marriage while the other supported the household, the court may deviate upward.

When combined gross income exceeds $500,000, the guidelines do not apply at all. In high-income cases, the court has full discretion to set both the amount and duration of maintenance based on the statutory factors.

Reviewable vs. Non-Reviewable Maintenance

Illinois courts can designate maintenance as either reviewable or non-reviewable. This distinction has significant practical consequences:

Reviewable maintenance means that the court retains jurisdiction to re-examine the maintenance award at a specified future date. At the review hearing, the court considers whether the receiving spouse has made reasonable efforts toward becoming self-supporting. If they have not, the court may reduce or terminate the award. The receiving spouse bears the burden of demonstrating that maintenance should continue.

Non-reviewable maintenance (also called “fixed-term” maintenance) means the award runs for a set period and terminates automatically at the end of that period. The court does not revisit the award unless one party files a motion for modification based on a substantial change in circumstances.

The choice between reviewable and non-reviewable maintenance depends on the facts. Reviewable maintenance is common in cases where the receiving spouse has the potential to become self-supporting with additional time, education, or training. Non-reviewable maintenance is more common in long marriages where the parties’ financial positions are unlikely to change significantly.

Modification of Maintenance

Either party may seek modification of a maintenance order by demonstrating a substantial change in circumstances. Common grounds include:

• Job loss or involuntary reduction in income of the payor
• Significant increase in the payee’s income or earning capacity
• Retirement of the payor at a reasonable age
• Cohabitation by the payee on a resident, continuing conjugal basis with another person (this creates a rebuttable presumption that maintenance should be modified or terminated)
• Disability or serious illness affecting either party’s ability to earn or need for support

Remarriage of the payee automatically terminates maintenance. The death of either party also terminates the obligation unless the court specifically orders that maintenance survives death (which is rare).

Tax Treatment After the TCJA

The Tax Cuts and Jobs Act of 2017 (TCJA) changed the federal tax treatment of maintenance for divorces finalized after December 31, 2018. Under current law:

• Maintenance is not tax-deductible for the payor. The paying spouse cannot deduct maintenance payments from their federal taxable income.
• Maintenance is not taxable income for the payee. The receiving spouse does not report maintenance as income on their federal tax return.

This is a significant shift from pre-2019 law, under which maintenance was deductible by the payor and taxable to the payee. The change effectively increases the after-tax cost of maintenance for the payor, because they pay maintenance with after-tax dollars. It also means the payee receives the full amount without a tax reduction.

Illinois state tax law follows the federal treatment. Maintenance is neither deductible nor taxable at the state level for divorces finalized after 2018.

This tax change should be factored into settlement negotiations. In the old regime, the tax deduction to the payor and the lower tax bracket of the payee often created a combined tax benefit that could be shared between the parties. That benefit no longer exists.

For a national overview of how spousal support works, see our guide on how alimony works. For more on the distinction between temporary and permanent support, see our article on temporary vs. permanent alimony.

What to Do Next

If spousal maintenance is an issue in your Illinois divorce, take these steps:

1. Calculate the guideline amount and duration. Run the formula using both parties’ net incomes and the length of the marriage. This gives you a baseline for negotiations.
2. Identify potential deviation factors. Consider whether any circumstances — health, career sacrifices, property division, high income — justify a departure from the guidelines.
3. Understand the tax impact. Maintenance is not deductible for the payor or taxable to the payee. Factor this into your settlement analysis.
4. Consider reviewable vs. non-reviewable. If you are the receiving spouse, non-reviewable maintenance provides more certainty. If you are the paying spouse, reviewable maintenance gives you a mechanism to reduce or end the obligation if circumstances improve.
5. Consult an Illinois family law attorney. The interaction between maintenance, property division, child support, and taxes makes these cases complex. Schedule a consultation with an attorney who handles maintenance cases in Illinois to evaluate your specific situation and develop a strategy.

Frequently Asked Questions

What factors are used to calculate child support?

Child support calculations typically consider both parents’ gross income, the number of children, the custody arrangement (parenting time), healthcare costs, childcare expenses, and any special needs of the child. Most states use either an income shares model or percentage of income model.

Can child support be different from the guideline amount?

Yes. Courts can deviate from the standard guidelines in certain circumstances, such as when a child has special needs, when one parent has extraordinarily high or low income, or when the existing arrangement involves unusual expenses. Either parent can request a deviation with proper justification.

How often can child support be reviewed?

Most states allow parents to request a review every two to three years or whenever there is a substantial change in circumstances. Changes that may warrant a review include significant income changes, changes in custody arrangements, or changes in the child’s needs.

How long does alimony last?

The duration depends on the type of alimony awarded and the length of the marriage. Short-term or rehabilitative alimony may last a few months to a few years, while long-term alimony after a lengthy marriage may continue until retirement, remarriage of the recipient, or death of either party.