Illinois Alimony Laws: Amount, Duration, and Enforcement

Illinois alimony laws, codified as “spousal maintenance” under the Illinois Marriage and Dissolution of Marriage Act, let a court order one spouse to pay the other during or after a divorce. The amount follows a statutory formula tied to both parties’ net incomes, the duration follows a fixed multiplier based on the length of the marriage, and whether maintenance is awarded at all turns on more than a dozen factors the judge weighs case by case.¹

Who Qualifies for Maintenance

Before any number gets calculated, the judge decides whether maintenance is appropriate at all. No single factor controls, but the ones that usually move the needle are the income gap between the spouses, how long the marriage lasted, and whether one spouse set aside a career to support the household.

The statute directs the court to look at:

Each party’s income and property, both marital and non-marital, including disability and retirement benefits.
Each spouse’s realistic earning capacity, factoring in education, job skills, and work history.
Whether one spouse delayed education, training, or employment to handle domestic responsibilities or support the other’s career.
How long the requesting spouse would need to acquire the training or education to find appropriate work.
The standard of living established during the marriage.
The age and physical and emotional health of both spouses.
Any contribution one spouse made to the other’s education, career, or business.
Any prenuptial or postnuptial agreement addressing maintenance.
Tax consequences of the property division.

One thing the court cannot consider is marital misconduct. Illinois bars fault from the maintenance decision, so an affair or other wrongdoing does not increase or decrease what gets ordered.¹

How the Amount Is Calculated

Illinois uses a guideline formula when the couple’s combined gross annual income is under $500,000 and neither spouse has an existing maintenance or child support obligation from a prior relationship. The calculation is:

33.3% of the payor’s net annual income, minus 25% of the payee’s net annual income. The result is the annual maintenance.

There is a hard cap built into the formula. The payee’s own income plus maintenance cannot exceed 40% of the couple’s combined net annual income. If the formula pushes the payee past that line, the award is reduced to bring the total back to 40%.¹

A quick worked example. Say the payor nets $120,000 a year and the payee nets $40,000. The formula produces $29,960 (33.3% of $120,000 is $39,960; subtract 25% of $40,000, or $10,000). Combined net income is $160,000, so the 40% cap sits at $64,000. Adding the formula amount to the payee’s income gives $69,960, which breaks the cap. The award gets trimmed to $24,000, which brings the payee’s total to exactly $64,000.

When combined gross income is above $500,000, or when the formula would produce an unjust result, the judge sets the amount using discretion rather than the guideline. A court that departs from the formula must state what the guideline figure would have been and explain the reason for deviating.¹

How Long Payments Last

Duration is just as formulaic. Multiply the length of the marriage by the factor that corresponds to that length:

Under 5 years: .20
5 to under 6 years: .24
6 to under 7 years: .28
7 to under 8 years: .32
8 to under 9 years: .36
9 to under 10 years: .40
10 to under 11 years: .44
11 to under 12 years: .48
12 to under 13 years: .52
13 to under 14 years: .56
14 to under 15 years: .60
15 to under 16 years: .64
16 to under 17 years: .68
17 to under 18 years: .72
18 to under 19 years: .76
19 to under 20 years: .80

A 10-year marriage produces about 4.4 years of maintenance; a 15-year marriage produces about 9.6 years. For marriages of 20 years or more, the court can order maintenance for a period equal to the length of the marriage or for an indefinite term.¹

The Four Types of Maintenance

An Illinois court can structure a maintenance award in several ways:

Fixed-term. Awarded for a set number of years, usually by applying the duration multipliers above. The recipient is expected to be self-sufficient when payments end, and once the term runs out, there is generally no extension unless the original order built in a review.
Indefinite. No end date. Courts typically use this for marriages of 20 years or more, or when the recipient realistically cannot become self-supporting because of age, disability, or chronic health conditions. It continues until a triggering event ends it.
Reviewable. Runs for a defined period with a court review built in. At the review, the judge decides whether to continue, modify, or end the award based on how circumstances have changed.
Temporary. Covers the lower-earning spouse while the divorce is still pending and ends when the court enters its final judgment.

Changing or Ending an Order

A maintenance order can be modified, but the person asking has to show a “substantial change in circumstances.” That standard is deliberately open-ended. Common examples include a major income shift for either party, a serious health event, or the recipient becoming fully self-supporting. A future event being foreseeable at the time the order was entered does not disqualify it, unless the order or the parties’ agreement specifically anticipated that exact event.²

The court will also weigh whether a change in employment was made in good faith, what the recipient has done to become self-supporting, how earning capacity has shifted on either side, and what property either party has acquired since the divorce. A payor cannot stop writing checks on their own judgment. Until a court actually modifies or terminates the order, the obligation stays in full force.

When Maintenance Ends Automatically

Unless the parties agreed otherwise in writing, maintenance ends automatically on any of these events:

Death of either party. The obligation ends when the payor or recipient dies.
Remarriage of the recipient. Maintenance terminates by operation of law on the date of the new marriage, and the payor is entitled to reimbursement for any payments made after that date.
Cohabitation. If the recipient is living with another person on a continuing conjugal basis, the court can terminate maintenance. The payor has to file a motion, and the judge looks at the length of the relationship, shared living arrangements, and combined finances. If cohabitation is found to have started before the motion was filed, the payor can recover payments made from that start date forward.²

Enforcement When a Payor Falls Behind

If the payor stops paying, the recipient has several enforcement tools. The most common is income withholding, which functions like wage garnishment. Under the Income Withholding for Support Act, every maintenance order entered since July 1, 1997 must include withholding provisions. Once served, the payor’s employer has 14 days to begin deducting the maintenance and must forward it to the State Disbursement Unit within 7 business days. When there is an arrearage, the withholding order has to include an additional amount of at least 20% of the current support to pay down the back balance.³

The recipient can also file a petition for contempt. If the court finds the payor had the ability to pay and willfully refused, the consequences can include fines, an order to cover the recipient’s attorney fees, a lump-sum judgment for the full arrearage, and in serious cases, jail time until the payor complies. Courts can also place liens on the payor’s property and intercept tax refunds. Illinois participates in the Uniform Interstate Family Support Act, so an Illinois order follows a payor who moves out of state.

Taxes on Maintenance Payments

For any divorce or separation agreement executed after December 31, 2018, maintenance is not deductible for the payor and is not taxable income for the recipient. The Tax Cuts and Jobs Act removed the federal deduction, and the change applies to every post-2018 agreement. Modifications of pre-2019 agreements can follow the new rules too, but only if the modification specifically says so.⁴

This changes the math on settlements. Under the old rules the payor’s deduction effectively reduced the real cost of each dollar paid, which often made higher numbers easier to agree on. Without the deduction, the payor absorbs the full cost, and the recipient keeps every dollar received. Settlement discussions should run the after-tax numbers on both households before signing.

Life Insurance to Secure Payments

For long-duration or indefinite awards, the court can require the payor to maintain life insurance so the recipient is not left without support if the payor dies first. For a policy the payor already owns, the court can allocate the death benefits, assign the right to name beneficiaries, or divide the premium obligation. For a new policy, the court can order the payor to cooperate with the application, but the recipient pays the premiums and holds the policy, subject to a reasonable coverage ceiling the court sets.¹

Failing to keep court-ordered coverage in force can lead to contempt proceedings.

1
Illinois General Assembly. Illinois Code 750 ILCS 5/504 – Maintenance
2
Illinois General Assembly. Illinois Code 750 ILCS 5/510 – Modification and Termination
3
Illinois General Assembly. Income Withholding for Support Act
4
Internal Revenue Service. Topic No. 452, Alimony and Separate Maintenance