Alimony in Illinois: Eligibility, Calculation, and Duration

Alimony in Illinois is called “maintenance,” and it is not automatic. A judge first decides whether the spouse asking for support actually needs it, then applies a statutory formula that uses each spouse’s income and the length of the marriage to set both the dollar amount and how long payments last. Combined income over $500,000 or an existing support obligation from a prior relationship takes the case out of the formula and into the judge’s discretion.

Who Qualifies for Maintenance

Before any numbers get run, the court has to find that maintenance is appropriate under 750 ILCS 5/504(a). The factors that carry the most weight in practice are the income and property each spouse will have after the divorce, the earning capacity of the spouse requesting support, and whether that earning capacity suffered because the spouse stayed home, delayed school, or otherwise put a career on hold for the family.¹

The standard of living during the marriage is a benchmark. A spouse who spent years as a homemaker may need support while getting the education or training to become employable. Age, health, and existing debts also come in. If the spouse asking for maintenance already has enough assets or income to meet reasonable needs, the court can deny the request outright.¹

Illinois is a no-fault state for this purpose. The statute requires the court to make its finding “without regard to marital misconduct,” so an affair or financial irresponsibility during the marriage does not change whether maintenance is awarded or how much it will be.¹

How the Amount Is Calculated

Once maintenance is warranted, the court looks to the guideline formula in 750 ILCS 5/504(b-1). The formula applies when two conditions are met: the couple’s combined gross annual income is under $500,000, and the payor has no existing child support or maintenance obligation from a prior relationship.¹

Watch the gross-versus-net distinction. The $500,000 threshold is measured against combined gross income, but the formula itself runs on net income. Take 33⅓% of the payor’s net annual income and subtract 25% of the payee’s net annual income. The result is the annual maintenance amount.¹

That amount is checked against a cap. When maintenance is added to the payee’s own net income, the total cannot exceed 40% of the couple’s combined net income. If the formula produces a figure that breaks that ceiling, the court reduces the award until it fits. The lower-earning spouse will not end up with a bigger share of household income than the higher earner.¹

When the Formula Does Not Apply

If combined gross income reaches $500,000 or more, or the payor already owes support from a previous relationship, the judge sets a non-guideline amount using the same eligibility factors from subsection (a): income, property division, earning capacity, standard of living, and the rest. A judge may also deviate from the guideline even when it technically applies, but must put in writing what the formula would have produced and why the deviation is justified.¹

How Long Maintenance Lasts

Duration tracks the length of the marriage, measured from the wedding to the date the divorce petition was filed. The statute assigns a multiplier to each year-range bracket. Multiply the marriage length by that factor to get the payment period. The multiplier starts at .20 for marriages under five years and climbs by .04 for each additional year:

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
20 years or more: maintenance for a period equal to the marriage length, or indefinitely, at the court’s discretion

A four-year marriage produces roughly 10 months of maintenance (4 × .20 = 0.8 years). A 12-year marriage produces about 6.2 years of payments (12 × .52). Once a marriage reaches 20 years, the court can order support for the full length of the marriage or make it permanent.¹

Fixed-Term or Reviewable

When maintenance is granted for a set period, the court has to label the award either fixed-term or reviewable, and the label matters. A fixed-term award ends on its designated date, and once that date passes, maintenance is permanently barred.¹

A reviewable award builds in a court date for the judge to reassess. At that hearing, the court can extend maintenance for another reviewable term, convert it to a fixed non-modifiable term, extend it indefinitely, or terminate it. For a recipient, a reviewable designation preserves the ability to ask for more time if things haven’t improved as expected.¹

Temporary Support While the Divorce Is Pending

Divorces take time, and bills do not wait. Under 750 ILCS 5/501, either party can ask the court for temporary maintenance while the case is pending. The request must be backed by a financial affidavit covering income, expenses, assets, and debts.²

Illinois uses a statewide standardized Financial Affidavit approved by the Illinois Supreme Court Commission on Access to Justice, filed with supporting documents like tax returns, pay stubs, and bank statements.³ Be careful with the numbers. Courts are required to impose sanctions, including attorney’s fees, against a party who files an affidavit that is intentionally or recklessly misleading.²

Taxes on Maintenance Payments

Federal tax treatment of maintenance changed when the Tax Cuts and Jobs Act of 2017 repealed the alimony deduction. For any divorce or separation agreement executed after December 31, 2018, the payor cannot deduct maintenance payments and the recipient does not include them in gross income.⁴

Divorces finalized on or before December 31, 2018 still use the older treatment unless a later modification expressly adopts the new rules. Modifying an old agreement does not flip the tax treatment on its own; the modification has to say so.⁴

For new agreements, the payor is paying with after-tax dollars and the recipient receives the money tax-free federally. Illinois has a separate formula for modifying pre-2019 orders that still carry the old tax treatment, using 30% of the payor’s gross income minus 20% of the payee’s gross income rather than the standard net-income formula.¹

Changing or Ending the Order

Maintenance does not always run the full originally ordered period. Under 750 ILCS 5/510, payments terminate automatically if the recipient remarries or if either party dies. The obligation also ends if the recipient starts living with another person in a relationship resembling a marriage, even without a wedding. The statute phrases this as cohabiting on a “resident, continuing conjugal basis.” If the payor can prove cohabitation began on a specific date, they are entitled to reimbursement for every maintenance payment made from that date forward.⁵

Outside those automatic triggers, either party can petition to modify the amount by showing a substantial change in circumstances. Common examples: an involuntary job loss, a serious medical problem, or a significant swing in either party’s income. The court reconsiders the original factors and also looks at whether an employment change was made in good faith.⁵

One caveat worth knowing before you sign anything. Parties can agree in writing to make maintenance non-modifiable as part of their settlement, and if the judgment includes that kind of agreement, the court generally cannot change the terms later even if circumstances shift.

Collecting Unpaid Maintenance

Illinois treats each missed maintenance payment as a separate judgment against the payor. Unpaid amounts accrue simple interest at 9% per year under 735 ILCS 5/2-1303, which adds up quickly on a growing balance.⁶

The recipient has several enforcement tools. A court can order the payor’s employer to withhold maintenance directly from wages through an income-withholding order, much like a child support garnishment. If payments still don’t come, the recipient can file a petition for a rule to show cause and ask the court to hold the payor in contempt. Contempt penalties can include fines and even jail for willful non-payment. Courts can also place liens on the payor’s property or seize bank accounts to recover what is owed.

1
Illinois General Assembly. 750 ILCS 5/504 – Maintenance
2
Illinois General Assembly. 750 ILCS 5/501 – Temporary Relief
3
Illinois Courts. Financial Affidavit
4
IRS. Topic No. 452, Alimony and Separate Maintenance
5
Illinois General Assembly. 750 ILCS 5/510 – Modification and Termination of Provisions for Maintenance
6
Illinois General Assembly. 735 ILCS 5/2-1303 – Interest on Judgment