Illinois Divorce Laws, Explained (2026)

"LaRocque Law: Understanding Divorce in Illinois"

Most of what people believe about Illinois divorce law comes from another state, a cousin’s friend’s case (whose name no one seems to know), or an internet forum. Some of it is surprisingly close. Most of it misses the mark, sometimes in ways that cost real money. This is the plain-English version of how divorce actually works in Illinois as of 2026: what the law requires, how the big decisions get made, and where people get surprised.

The statute behind almost all of this is the Illinois Marriage and Dissolution of Marriage Act, 750 ILCS 5. You don’t need to read it. You do need to know what it says about your situation, and that is what this is for.

Is Illinois a No-Fault Divorce State?

Yes, and it has been a pure no-fault state since January 1, 2016. There is exactly one ground for divorce in Illinois: irreconcilable differences that have caused the irretrievable breakdown of the marriage, where efforts at reconciliation have failed or would not be in the family's best interests. Adultery, abandonment, cruelty, and the other fault grounds were repealed. You cannot file on them, and your spouse cannot use them against you. 750 ILCS 5/401.

That has two practical consequences people do not expect. First, nobody has to agree to the divorce. If one spouse says the marriage has broken down, the case moves forward whether or not the other spouse signs anything. A spouse who refuses to participate can be defaulted. Second, the reason the marriage ended does not affect who gets what. The statute says property and maintenance are decided "without regard to marital misconduct." An affair is not a financial issue in an Illinois divorce unless marital money was spent on it, which is a different concept called dissipation and is covered below.

Grounds for Divorce in Illinois and the Six-Month Rule

If spouses have lived separate and apart continuously for at least six months immediately before judgment, Illinois law creates an irrebuttable presumption that the irreconcilable-differences requirement has been met. This is not a six-month waiting period before filing. If six months have not passed, the court must still determine whether the statutory ground has been proved. 750 ILCS 5/401.

Living “separate and apart” does not necessarily mean maintaining two addresses. Whether spouses sharing a home have in fact separated depends on their circumstances; do not assume that continuing to live under one roof either satisfies or defeats the requirement.

Residency Requirements

One spouse has to have been a resident of Illinois (or stationed here in the military) for at least 90 days before the case is filed or before the judgment is entered. Which county you file in is a separate question of venue, and in the Chicago area it is usually where either spouse lives. For most of our clients, that means Cook County at the Daley Center, DuPage County in Wheaton, or Will County in Joliet. The law is the same in all three. The local procedure and the pace are not, and it is worth working with a lawyer who is in those courthouses regularly and knows the difference.

The Divorce Process in Illinois: Step by Step

A spouse starts a case by filing a Petition for Dissolution of Marriage and arranging proper service. The summons generally calls for the responding spouse to answer or appear within 30 days after service. If the spouse does not participate, a default may be possible—but the court still must have a proper basis for the relief it grants. Ill. Sup. Ct. R. 101(d)–(e)

Early in the case, both sides exchange a sworn financial affidavit listing income, expenses, assets, and debts, along with supporting records. In Cook County, the petitioner must serve it within 30 days after serving the initial pleading, and the respondent within 30 days after filing an appearance, or at least seven business days before a hearing if that comes first. It is served on the other side, not filed with the court. If circumstances change materially before a later hearing, an updated affidavit has to be served. Other counties set their own deadlines, so follow the applicable local rule and any court order. Cook Cnty. Cir. Ct. R. 13.3.1

The Financial Affidavit might be the single most important document you fill out in a divorce. It is the starting point for how the financial issues get resolved. Judges rely on it, opposing counsel scrutinizes it, and misstatements on it have consequences. We wrote a separate post on the financial affidavit because people often underestimate its significance.

When parental responsibilities are at issue, parents generally must submit proposed parenting plans within 120 days after a petition for allocation of parental responsibilities is filed or served, subject to extensions and exceptions. The court generally orders mediation to help develop or implement a plan unless it finds an impediment to mediation. 750 ILCS 5/602.10

From there, the case goes one of two ways. If the spouses reach agreement on everything, the terms go into a Marital Settlement Agreement (and a Parenting Plan and Allocation Judgment if there are children), and the case is finalized at a short hearing called a prove-up.

In Cook County, an uncontested case can often be finished by affidavit without anyone appearing in court. If the spouses cannot agree, the case goes through discovery, temporary motions, possibly outside valuations, and eventually a trial where the judge decides the open issues.

See our Divorce Timeline for a detailed breakdown of the process.

Divorce in Illinois: Who Gets What

This is where "Illinois is a 50/50 state" causes the most damage. It is not.

Illinois is an equitable distribution state. The court first classifies everything as marital or non-marital, then divides the marital property in "just proportions." Just proportions is often close to equal, but the statute does not require equal, and the court considers a list of factors including the length of the marriage, each spouse's contribution to acquiring and preserving the property (including contributions as a homemaker), each spouse's income and earning capacity going forward, the age and health of each spouse, any prenuptial or postnuptial agreement, and whether either spouse dissipated marital assets.

Marital property is, broadly, everything either spouse acquired during the marriage, regardless of whose name is on it. That includes the house, the retirement accounts, the business, and the debt. Non-marital property is what a spouse owned before the marriage, received by gift or inheritance during the marriage, or excluded by a valid agreement, plus what can be traced back to those sources. Non-marital property stays with the spouse who owns it and is not divided.

The catch is that the lines blur constantly. Pre-marital money that gets deposited into a joint account, a house bought before the wedding but paid down with marital income, an inheritance used to renovate the marital home: each of these raises questions of commingling, transmutation, and reimbursement, and the answer depends on records. The spouse claiming something is non-marital has the burden of proving it. Without documentation, the presumption is that it is marital.

What a Spouse Is Entitled to in an Illinois Divorce

The honest answer is that the statute does not entitle either spouse to anything by virtue of being the wife or the husband.

Illinois law is gender-neutral throughout. What a spouse receives depends on the classification and division of property, whether maintenance is appropriate, and, if there are children, how support and parenting time are allocated.

A spouse who left the workforce to raise children is not penalized for it; homemaker contributions are an express factor, and the resulting gap in earning capacity is central to the maintenance analysis. But there is no formula that says the wife gets the house, or half, or anything else automatically.

Who Gets the House in a Divorce in Illinois

Usually, whoever can afford it, if anyone can. The house is marital property if it was acquired during the marriage or paid for with marital funds, and its equity gets divided along with everything else.

Three outcomes are common: one spouse keeps the house and buys out the other's share (often by refinancing or by giving up other assets of equal value), the house is sold and the proceeds divided, or one spouse stays temporarily, most often the parent with the majority of parenting time, with a sale or buyout scheduled for later.

Moving out during the case does not forfeit your interest in the house. That is one of the most repeated pieces of false information I’ve seen confidently shared online. It can set a status quo for the parenting schedule that is hard to undo later, so make the decision deliberately, but the equity is still yours.

Dissipation

Dissipation is the use of marital funds for a purpose unrelated to the marriage at a time when the marriage is undergoing an irretrievable breakdown. Money spent on an affair, gambling losses, large unexplained withdrawals, or transfers to relatives during the breakdown period are the typical examples. If proven, the dissipated amount is charged against the spending spouse's share. Worth noting, it is not an automatic dollar-for-dollar payment to the other spouse. 750 ILCS 5/503(d).

The statute also limits how far back a claim may reach based on when the claimant knew or should have known of the spending and when the divorce petition was filed. If you suspect dissipation, preserve the records and raise it promptly. 750 ILCS 5/503(d)(2)

There are procedural rules. A dissipation claim requires a notice of intent identifying, at minimum, when the breakdown began, the property at issue, and when the alleged dissipation occurred. The notice is due no later than 60 days before trial or 30 days after discovery closes, whichever is later. 750 ILCS 5/503(d)(2). Miss that deadline and the claim is waived. If you suspect dissipation, gather the statements early and raise it with your lawyer before the deadlines pass.

Maintenance (What Other States Call Alimony)

Illinois calls it maintenance, and it is decided in two steps.

First, the court decides whether maintenance is appropriate at all, based on factors including each spouse's income and needs, the standard of living during the marriage, the length of the marriage, and the time the requesting spouse needs to become self-supporting. Maintenance is not automatic. 750 ILCS 5/504(a)

Second, if maintenance is appropriate and the spouses' combined gross annual income is under $500,000, the amount and duration are set by a statutory guideline formula. The amount is 33⅓% of the paying spouse's net income minus 25% of the receiving spouse's net income, capped so that the receiving spouse does not end up with more than 40% of the combined net income. The duration is the length of the marriage multiplied by a percentage that increases with each year of marriage, from 20% for a marriage under five years up to 80% of the marriage's length at 19 years. At 20 years or more, the court can order maintenance for the full length of the marriage, or indefinitely.

Two things people get wrong. Remarriage ends maintenance automatically. Cohabitation on a resident, continuing conjugal basis can end it too, but not on its own — the paying spouse has to go to court and prove the relationship. Until a judge rules, the obligation continues. And since 2019, maintenance is not tax-deductible to the payer or taxable to the recipient under federal law, which is why the formula is now based on net rather than gross income. Our maintenance calculator applies the current guideline; the practical guide walks through when courts deviate from it.

Other statutory rules may call for a non-guideline award. 750 ILCS 5/504(b-1).

Also, see our page on maintenance and our maintenance calculator.

Child Support in Illinois

Illinois generally uses an income-shares model. The calculation starts with each parent’s monthly net income, combines those incomes, and uses the state’s schedule to find a basic support obligation for the number of children. Each parent is assigned a share based on income. The receiving parent’s share is presumed to be spent directly on the child rather than paid to the other parent. The court can depart from the guideline amount when the statutory requirements for a deviation are met. 750 ILCS 5/505(a)(1.5), (2), (3.4)

As of 2026, a different shared-care calculation applies when each parent has at least 146 overnights a year with the child. That calculation accounts for both parents’ incomes and parenting time, then offsets their respective obligations. Do not assume that the parent with fewer overnights will always be the one who pays. 750 ILCS 5/505(a)(3.8)

Current child support ordinarily continues until 18, or, if the child is still attending high school, until graduation or 19, whichever comes first. An order must state a termination date, and unpaid arrears do not disappear when current support ends. Separately, a court may order contributions toward a child’s college, vocational, or other qualifying educational expenses, subject to statutory conditions and limits. 750 ILCS 5/505(a), (g) · 750 ILCS 5/513

A parent’s job loss or lower income does not automatically change an existing order. A parent who believes support should change should promptly seek a modification. If a parent is voluntarily unemployed or underemployed, the court may use potential income, but it must follow the statute’s requirements for imputing income. Unpaid support can accrue interest. 750 ILCS 5/510(a) · 750 ILCS 5/505(a)(3.2a)(3.2b), (b).

A change is scheduled for January 1, 2027. The enacted law expands the shared-care calculation to parents with at least 110 overnights, or qualifying overnight equivalents, and provides an adjustment below 146. This article describes 2026 law; check the rules in force when your support calculation is made. 750 ILCS 5/505 (effective Jan. 1, 2027)

You can explore an estimate with our Illinois child support calculator. A calculator is a starting point, not a court order; confirm that it reflects the law applicable to your case.

Child Custody Laws in Illinois: Parenting Time and Decision-Making

Illinois retired the word "custody" in 2016. The law now allocates two things separately: parental responsibilities, meaning who makes significant decisions about education, health care, religion, and extracurricular activities, and parenting time, meaning the schedule of when the children are with each parent. 750 ILCS 5/600(d)–(e) · 750 ILCS 5/602.5(b)

The court uses the child’s best interests to decide both issues. Illinois law does not make a mother, a father, or a 50/50 schedule the automatic choice. For parenting time, the court considers such matters as the child’s needs, prior caretaking, the parents’ locations and schedules, their ability to cooperate, and any relevant safety concerns. 750 ILCS 5/602.5 · 750 ILCS 5/602.7

A child does not gain the legal right to choose a residence at a specified age. The child’s wishes are a factor, considered in light of maturity and the ability to express an independent preference. A judge may interview a child in chambers under statutory procedures, but the decision remains the court’s. 750 ILCS 5/602.7(b)(2) · 750 ILCS 5/604.10(a)

Decision-making can be allocated jointly or to one parent, and it can be split by category.

Moving with a Child

Illinois has specific relocation rules for a parent allocated a majority of parenting time or either parent allocated equal parenting time. A move within Illinois of more than 25 miles from a child’s primary residence in Cook, DuPage, Kane, Lake, McHenry, or Will County meets the statutory definition of relocation. For a child’s primary residence in another Illinois county, the in-state threshold is more than 50 miles. An out-of-state move is a relocation if it is more than 25 miles from the child’s current primary residence. Distance is measured by an internet mapping service. 750 ILCS 5/600(g).

A qualifying move requires written notice, generally at least 60 days in advance unless that is impracticable or the court orders otherwise. If the other parent signs the notice and it is filed, the move may proceed without further court action. If the other parent objects or does not sign—or the parents cannot agree on necessary changes to the parenting plan—the relocating parent must petition the court for permission. 750 ILCS 5/609.2.

Prenuptial and Postnuptial Agreements

A premarital agreement can address property rights and the modification or elimination of spousal support, but it cannot adversely affect a child’s right to support. A party resisting enforcement may challenge a premarital agreement under the Illinois Uniform Premarital Agreement Act. An agreement is unenforceable if it was not signed voluntarily, or if it was unconscionable when signed and the challenging spouse did not receive fair disclosure, did not waive disclosure in writing, and did not otherwise know the other’s finances. Even an otherwise enforceable support limitation may be affected by undue hardship arising from circumstances not reasonably foreseeable when the agreement was signed. 750 ILCS 10/4, 750 ILCS 10/7.

Postnuptial agreements, signed after the wedding, are not the same thing. Postnuptial agreements are highly scrutinized by the court, so you want to make sure it’s done right. If you have either, bring it to your first meeting. It changes the analysis of everything above.

How Long Does a Divorce Take in Illinois?

The most asked question is “how long is this going to take?” The reason a lot of attorneys don’t answer that question directly is because it’s just an impossible question to answer. There is a wide range of possible timelines, many of which are hard to predict with certainty. An uncontested divorce, where both spouses agree on every single term, can have a quick turnaround time by submitting the documents by affidavit in Cook County. An uncontested divorce in DuPage, for example, might turn contested, and two years later you’re in a month-long trial. Both may have come to the consultation with the same facts. Which makes it really hard to answer the second most asked question: “how much is this going to cost?”

Delays in a case can include lengthy business valuations, a deadlock on parenting issues, or just a busy judge. However, at the end of the day, you and (perhaps unfortunately) your spouse are the single biggest drivers of timeline. It just depends on how much the two spouses disagree and how long it takes to find common ground.

After the Divorce

Some orders can change after judgment, but not every provision is modifiable on the same terms. Child support, maintenance, and parenting arrangements have different modification rules and exceptions. Property provisions are generally final, apart from grounds that justify reopening a judgment. If circumstances change, do not assume an existing payment or parenting obligation has changed with them. 750 ILCS 5/502(f) · 750 ILCS 5/510 · 750 ILCS 5/610.5

Frequently Asked Questions

Does my spouse have to agree to the divorce?

No. The court can grant a divorce if the legal requirements are met even if one spouse objects or does not participate.

Must we live separately for six months?

No. Six months living separate and apart creates an irrebuttable presumption about irreconcilable differences; it is not a mandatory wait before filing.

Is Illinois a 50/50 state?

No. Marital property is divided in just proportions, not automatically equally, and there is no automatic equal-parenting-time schedule.

Does an affair affect the financial result?

Marital misconduct itself does not determine property division or maintenance. Spending marital property on an affair may present a separate dissipation question.

Who pays maintenance?

Either spouse may be ordered to pay if the court finds maintenance appropriate. The guideline formula does not apply merely because combined gross income is below $500,000; other statutory conditions and exceptions matter.

At what age can a child choose where to live?

There is no specified age at which the child decides. The child’s wishes are one best-interests factor.

How much does a divorce cost?

It depends on the work required, including whether the parties resolve financial and parenting issues by agreement or litigate them. Ask about fees and the likely next steps for your case.

Talk to Us

LaRocque Law handles divorce, allocation of parental responsibilities, child support, maintenance, and related family law matters in Cook, DuPage, and Will Counties. Our attorneys meet with clients by appointment in person here in Chicago or by Zoom. Call (312) 584-3456 or schedule a consultation online at larocque-law.com.

This article provides general information about Illinois law as of 2026 and is not legal advice. Reading it does not create an attorney-client relationship, and past results do not guarantee future outcomes. Statutes and guideline figures change; speak with an attorney about your own situation.