Divorce Laws in Illinois: Complete 2026 Guide

Illinois is exclusively a no-fault divorce state. As of January 1, 2016, all fault-based grounds for divorce were eliminated from Illinois law. The sole ground for dissolution of marriage is irreconcilable differences that have caused the irretrievable breakdown of the marriage, as set forth in 750 ILCS 5/401(a). The court must determine that efforts at reconciliation have failed or that future attempts at reconciliation would be impracticable and not in the best interests of the family. Prior to 2016, Illinois recognized multiple fault-based grounds including adultery, mental cruelty, physical cruelty, habitual drunkenness, drug addiction, desertion, and others. The shift to a purely no-fault system streamlined the divorce process and reduced the adversarial nature of proceedings. Under the current law, a spouse filing for divorce does not need to prove any wrongdoing by the other party — only that the marital relationship has broken down beyond repair. Under 750 ILCS 5/401(a-5), if the parties have lived separate and apart for a continuous period of not less than six months immediately preceding the entry of the judgment of dissolution, there is an irrebuttable presumption that irreconcilable differences have caused the irretrievable breakdown of the marriage and that reconciliation has failed. Importantly, 'separate and apart' does not necessarily mean living in different residences — spouses may live under the same roof while leading separate lives. This no-fault framework applies to all divorces in Illinois, whether contested or uncontested. The elimination of fault grounds means that marital misconduct such as infidelity, while emotionally significant, has no bearing on the legal grounds for obtaining the divorce itself. However, it is worth noting that while fault does not affect the grounds for divorce or property division, certain conduct may still be relevant in custody and parenting determinations if it affects the best interests of the child.

To file for divorce in Illinois, at least one spouse must have been a resident of Illinois for a minimum of 90 days immediately preceding the filing of the divorce petition or the making of the court's finding on grounds. This requirement is established under 750 ILCS 5/401(a). Military members stationed in Illinois may also satisfy this requirement if they have maintained their military presence in the state for 90 consecutive days. The 90-day residency requirement applies to only one spouse — not both. This means that if one spouse lives in Illinois and has been a resident for at least 90 days, they can file for divorce in the state even if the other spouse resides in a different state or country. The filing spouse verifies their residency through a sworn statement in the Petition for Dissolution of Marriage. Illinois courts rely on this signed writing as sufficient verification of residency under normal circumstances. Regarding venue (which county to file in), Illinois law under 750 ILCS 5/104 provides that divorce proceedings must be commenced in the county where either the petitioner (filing spouse) or the respondent (other spouse) resides. If the parties reside in different counties in Illinois, the petitioner may file in either county. If neither party resides in the county where the petition is filed, the petitioner must file a motion explaining why they chose that particular county and requesting a waiver of the venue requirement. For cases involving children, there are additional jurisdictional considerations under the Uniform Child-Custody Jurisdiction and Enforcement Act (UCCJEA). Generally, the child must have resided in Illinois for at least six months before the filing for the court to have jurisdiction over custody matters. The residency requirement for the divorce itself, however, remains at 90 days for at least one spouse.

Illinois follows the principle of equitable distribution when dividing marital property in a divorce, as governed by 750 ILCS 5/503. Equitable distribution does not mean equal; rather, the court divides marital property in 'just proportions' after considering a comprehensive set of statutory factors. Illinois is not a community property state, and a 50/50 split is not presumed or required. The first step in property division is classifying assets and debts as either marital or non-marital property. Under 750 ILCS 5/503(a), non-marital property includes property acquired before the marriage, property acquired by gift or inheritance, property acquired in exchange for non-marital property, and property excluded by a valid prenuptial or postnuptial agreement. Under 750 ILCS 5/503(b), all property acquired by either spouse after the marriage and before the judgment of dissolution is presumed to be marital property. Non-marital property is assigned to the owning spouse, while marital property is subject to equitable division. When dividing marital property, the court considers twelve statutory factors under 750 ILCS 5/503(d), including: each party's contribution to the acquisition, preservation, or increase or decrease in value of the marital estate (including homemaker contributions); dissipation of marital assets; the value of property assigned to each spouse; the duration of the marriage; the relevant economic circumstances of each party; any obligations from a prior marriage; any prenuptial or postnuptial agreements; age, health, occupation, and employability of each spouse; custodial provisions for children; whether the property division is in lieu of or in addition to maintenance; each party's future earning capacity; and the tax consequences of the distribution. Importantly, marital misconduct is not a factor in property division under Illinois law. The court is prohibited from considering fault when dividing property. However, the concept of 'dissipation' — where one spouse wastes marital assets for non-marital purposes during the breakdown of the marriage — is a legitimate factor under 750 ILCS 5/503(d)(2). A spouse who dissipated marital assets may receive a smaller share of the remaining property. The court may also divide complex assets like pensions, stock options, business interests, and retirement accounts, often using tools like Qualified Domestic Relations Orders (QDROs).

Spousal support in Illinois is called 'maintenance' and is governed by 750 ILCS 5/504. The court may award maintenance to either spouse, regardless of gender, in amounts and for periods of time the court deems just. Maintenance is determined without regard to marital misconduct. The court first determines whether a maintenance award is appropriate by evaluating all relevant factors, including: the income and property of each party; the needs of each party; the present and future earning capacity of each party; any impairment of earning capacity due to domestic duties; the time necessary for the recipient to acquire sufficient education or training; the standard of living established during the marriage; the duration of the marriage; the age and health of each party; tax consequences; and contributions to the education or career of the other spouse. Illinois uses a statutory guideline formula for calculating the amount and duration of maintenance in cases where the combined gross annual income of both parties is less than $500,000 and neither party has a prior support obligation from another relationship. Under 750 ILCS 5/504(b-1)(1)(A), the annual maintenance amount is calculated as 33.33% of the payor's net annual income minus 25% of the payee's net annual income. However, the resulting amount, when added to the payee's net income, cannot exceed 40% of the combined net income of both parties. The duration of maintenance is determined by multiplying the length of the marriage at the time the action was filed by a statutory factor under 750 ILCS 5/504(b-1)(1)(B). The duration multipliers are: 0.20 for marriages of 5 years or less; 0.40 for marriages over 5 but under 10 years; 0.60 for marriages of 10 to 15 years; and 0.80 for marriages of 15 to 20 years. For marriages lasting 20 years or more, the court may order maintenance for a period equal to the length of the marriage or for an indefinite term. The court designates maintenance as fixed-term, indefinite, or reviewable under 750 ILCS 5/504(b-4.5). Maintenance terminates upon the death of either party, the remarriage of the recipient, or if the recipient cohabitates with another person on a resident, continuing, conjugal basis (750 ILCS 5/510). A notable change effective January 1, 2025, eliminated the provision that maintenance obligations do not accrue during incarceration — maintenance now continues to accrue while the payor is imprisoned, and arrears are enforceable upon release. The court retains the ability to deviate from the guideline formula when circumstances warrant, and maintenance may be modified upon a showing of a substantial change in circumstances.

Illinois replaced the traditional terms 'custody' and 'visitation' with 'allocation of parental responsibilities' and 'parenting time' effective January 1, 2016. Parental responsibilities are divided into two components: significant decision-making responsibility (covering education, health, religion, and extracurricular activities) under 750 ILCS 5/602.5, and parenting time (the physical schedule of when each parent has the child) under 750 ILCS 5/602.7. Both are determined according to the best interests of the child standard. For significant decision-making responsibilities, the court considers factors under 750 ILCS 5/602.5(c), including: the wishes of the parents; the child's needs; the child's adjustment to home, school, and community; the mental and physical health of all individuals involved; the ability of the parents to cooperate in decision-making; the level of each parent's participation in past decision-making; any prior agreements between the parents; and any history of domestic violence or abuse. The court can allocate decision-making jointly to both parents, or assign sole decision-making to one parent in some or all significant areas. For parenting time, the court considers a similar but distinct set of factors under 750 ILCS 5/602.7(b), including: the wishes of each parent; the wishes of the child (taking into account maturity); the amount of time each parent spent performing caretaking functions in the 24 months preceding the filing; any prior agreements or course of conduct between parents; the interaction of the child with parents, siblings, and significant others; the child's adjustment to home, school, and community; the mental and physical health of all parties; the distance between the parents' homes; whether a restriction on parenting time is appropriate; and the willingness of each parent to facilitate and encourage a close relationship between the child and the other parent. Illinois courts may also require parents to submit a parenting plan and, in many counties, to complete a mandatory parenting education course before the divorce can be finalized. The court may appoint a Guardian ad Litem (GAL) or a child representative to advocate for the child's best interests in contested cases. If parents cannot agree on a parenting plan, the court will impose one based on the statutory best interest factors.

To begin a divorce in Illinois, one spouse (the petitioner) files a Petition for Dissolution of Marriage with the circuit court in the county where either spouse resides, as required by 750 ILCS 5/104. The petition must include specific information under 750 ILCS 5/411, including: the age, occupation, and residence of each party and length of residence in Illinois; the date and place of the marriage; a statement that the jurisdictional requirements have been met; the names, ages, and addresses of all minor children; and any proposed arrangements for support, parenting responsibilities, and maintenance. The appropriate filing fee must be paid at the time of filing. After filing, the petitioner must formally notify the other spouse (the respondent) by having copies of the divorce papers served. Service is typically accomplished by having a sheriff's deputy or licensed process server personally deliver the papers to the respondent. If the respondent cannot be located after diligent efforts, service by publication may be permitted. The respondent then has 30 days to file an Appearance and an Answer. The respondent may also file a Counter-Petition raising their own claims. Filing fees in Illinois vary by county. For example, in Cook County, the filing fee for a divorce petition is approximately $388, while in DuPage County it is approximately $348. Madison County charges approximately $314 to file the petition plus $189 for the respondent's answer. Many other counties fall in the $250–$400 range. Additional costs may include fees for service of process, filing motions, parenting education classes, mediation, and other proceedings. If a party cannot afford the fees, they may file an Application for Waiver of Court Fees asking the court to proceed without requiring payment. Illinois also offers a Joint Simplified Dissolution procedure for couples who meet specific criteria: they have been married less than eight years, have no children, neither spouse has an interest in real estate, combined gross annual income is under $60,000, total marital property is under $50,000, and both spouses waive any right to maintenance. This streamlined process requires both spouses to appear together and can be finalized in a single court appearance. For all other divorces, the process will involve case management conferences, disclosure of financial information, negotiation or mediation, and potentially a trial if issues remain unresolved. In Illinois, divorce cases are filed in the circuit courts, which are the state's trial-level courts of general jurisdiction. Illinois has 24 judicial circuits covering all 102 counties. Within the circuit court system, larger counties typically have a dedicated Domestic Relations or Family Division that handles divorce, custody, and other family law matters. In Cook County, for example, the Domestic Relations Division has multiple courthouses across the county's districts, and cases are assigned based on the residential addresses of the parties. In smaller counties, there may not be a separate family law division. Instead, one or two circuit judges handle family law cases along with other civil and criminal matters. Regardless of county size, the circuit court has exclusive original jurisdiction over divorce cases in Illinois. Federal courts do not have jurisdiction over divorce proceedings. Appeals from circuit court divorce judgments are taken to the Illinois Appellate Court, which is organized into five districts across the state. The appellate court reviews the trial court's decisions for legal errors. Further appeal may be sought from the Illinois Supreme Court, although the Supreme Court has discretion in selecting which cases it will hear. A party must challenge a divorce judgment within 30 days of entry or, in cases involving fraud or duress, file within two years to seek to set aside the judgment. The Illinois court system also includes administrative child support proceedings that operate separately from the family law courts. Under 750 ILCS 25/7, the Illinois Department of Healthcare and Family Services may initiate expedited child support proceedings for state residents. These administrative proceedings can establish or modify child support orders and operate in every county alongside the regular circuit court system.

Illinois does not impose a traditional mandatory waiting period between filing for divorce and the entry of a final judgment of dissolution in the same way some states do. However, there are time-related requirements that effectively create waiting periods. The most significant time-related requirement involves the irrebuttable presumption of irreconcilable differences. Under 750 ILCS 5/401(a-5), if the parties have lived separate and apart for a continuous period of not less than six months immediately preceding the entry of the judgment of dissolution, there is an irrebuttable presumption that the marriage has irretrievably broken down. This six-month separation period can be waived if both parties agree that the marriage is irretrievably broken, but if one party contests the grounds, the six-month separation must be demonstrated before the court can enter the judgment. Importantly, living 'separate and apart' in Illinois does not necessarily require maintaining separate households. Courts have recognized that spouses can live separate and apart while residing under the same roof, provided they are leading essentially separate lives. This can include sleeping in different rooms, not sharing meals, maintaining separate finances, and not engaging in marital relations. For uncontested divorces where both parties agree on all issues, the process can move relatively quickly after the 90-day residency requirement is met. There is no statutory minimum waiting period between the filing of the petition and the finalization of the divorce if both spouses cooperate. However, practical court scheduling delays — including mandatory case management conferences and, in cases with minor children, required completion of parenting education classes — mean that even uncontested divorces typically take several weeks to a few months to finalize.