750 ILCS 5 - Illinois Marriage and Dissolution of Marriage Act

Illinois is a purely no-fault divorce state. The only ground is that 'irreconcilable differences have caused the irretrievable breakdown of the marriage.' If the parties have lived separate and apart for 6 months or more, there is an irrebuttable presumption that irreconcilable differences exist. Living 'separate and apart' does not require separate residences — it means the parties are no longer functioning as a married couple.

Effective: 2016

At least one spouse must have been a resident of Illinois, or stationed in Illinois as a member of the armed forces, for at least 90 days before the court can enter a judgment of dissolution. There is no pre-filing waiting period — you can file immediately upon meeting residency requirements.

Effective: 2016

Either spouse may file for legal separation instead of dissolution. The court can enter a judgment of legal separation using the same residency and irreconcilable differences standards as dissolution. Legal separation does not end the marriage but allows for orders on property, support, and parenting.

Effective: 2016

Illinois is an equitable distribution state — marital property is divided fairly, not necessarily 50/50. The court considers 12 statutory factors including each spouse's contribution to acquiring the property, dissipation of assets, marriage duration, each party's economic circumstances, and tax consequences. The court must classify each asset as marital or non-marital and make specific factual findings supporting the property award.

Effective: 2016

All property acquired by either spouse during the marriage is presumed marital property. Non-marital property includes gifts, inheritances, property acquired before marriage, and property excluded by a valid prenuptial agreement. Non-marital property transferred into co-ownership between spouses becomes marital property. The court divides only marital property — non-marital property stays with its owner.

Effective: 2016

If the court finds a companion animal is marital property, it must allocate sole or joint ownership and responsibility for the animal. The court considers the well-being of the companion animal when making this determination. Parties may also address pet ownership in their marital settlement agreement.

Effective: 2018

Spouses may enter a written agreement covering property division, maintenance, parenting responsibilities, and support of children. Property provisions in an agreement are never modifiable after the judgment is entered. The agreement may also limit or preclude modification of other terms such as maintenance. The court will incorporate the agreement into the judgment if it finds the terms are not unconscionable.

Effective: 2016

Illinois replaced 'custody' with 'allocation of parental responsibilities' in 2016. The court allocates decision-making authority for significant issues — education, health, religion, and extracurricular activities — to one or both parents based on the child's best interests. The court considers 15 factors including each parent's wishes, the child's adjustment, the parents' ability to cooperate, and any history of domestic violence or abuse.

Effective: 2016

The court allocates parenting time (formerly 'visitation') according to the child's best interests using 17 statutory factors. Key factors include the amount of time each parent spent performing caretaking functions in the 24 months before filing, each parent's willingness to facilitate a relationship with the other parent, and the child's wishes. Both parents are presumed fit unless evidence shows parenting time would seriously endanger the child.

Effective: 2016

All parents must file a proposed parenting plan — jointly or separately — within 120 days of service or filing of a petition. The plan must include allocation of decision-making, parenting time schedules, the child's residential address for school enrollment, and provisions for notice of address changes. If parents cannot agree, the court orders mediation. If mediation fails, the court conducts a trial to determine the plan.

Effective: 2016

A parent with majority or equal parenting time who wants to relocate with the child must give the other parent at least 60 days' written notice. If the other parent objects, the relocating parent must seek court approval. The court considers 11 factors including the child's relationship with both parents, the impact on the child's development, and the feasibility of preserving the parent-child relationship. Relocation constitutes a substantial change in circumstances for modification purposes.

Effective: 2016

A deployed military parent may designate a person known to the child to exercise reasonable substitute parenting time on their behalf during deployment, if the court determines it is in the child's best interests. The court also considers the terms of a parent's military family-care plan when allocating parenting time.

Effective: 2016

The court may award maintenance to either spouse without regard to marital misconduct. For combined gross incomes under $500,000, the guideline formula is 33⅓% of the payor's net income minus 25% of the payee's net income, capped so the payee does not receive more than 40% of combined net income. Duration is calculated by multiplying marriage length by a statutory factor (0.20 for 5 years to 0.80 for 20 years). For marriages of 20+ years, the court may order indefinite maintenance.

Effective: 2019

Illinois uses the Income Shares Model, meaning child support is based on both parents' combined net income and proportionally divided. Each parent's net income is calculated from all sources minus allowed deductions (taxes, Social Security, Medicare). The basic support obligation comes from a statutory schedule updated annually (most recently March 2025). When each parent has 146 or more overnights per year, a shared-parenting adjustment with a 1.5 multiplier and cross-credit applies.

Effective: 2017

Maintenance and child support orders may be modified upon a showing of a substantial change in circumstances. Child support may also be modified without showing substantial change if the current order differs from guidelines by at least 20% (and at least $10/month). Maintenance terminates upon the recipient's remarriage or cohabitation on a continuing conjugal basis. As of 2025, maintenance arrears may now accrue during a payor's incarceration.

Effective: 2025

The court may order either party to pay a reasonable amount for the other party's attorney fees and costs after considering both parties' financial resources. In enforcement proceedings, the court must order the non-compliant party to pay the prevailing party's fees if the failure to comply was without compelling cause. Attorney fees may not be contingent on securing a dissolution or based on the amount of support or property received, and non-refundable retainers are prohibited.

Effective: 2016

A petition for dissolution must allege that irreconcilable differences have caused the irretrievable breakdown of the marriage. Since Illinois eliminated all fault-based grounds in 2016, the petition does not need to allege any specific misconduct. The petition must also include information about children, property, and pending related cases.

Effective: 2016

Couples may use a streamlined process if they meet all requirements: no minor children, total marital property under $50,000 (after debts), combined annual income under $60,000 (neither spouse earning over $30,000), married less than 8 years, no retirement benefits (except IRAs under $10,000 combined), neither spouse owns real estate, and both waive maintenance. This process can be completed in as little as 30 days.

Effective: 2016

Either party may request temporary orders while the divorce is pending, including temporary maintenance, child support, use of the marital home, and restraining orders. Temporary support is determined on a summary basis using financial affidavits, tax returns, and pay stubs. The court imposes penalties for intentionally or recklessly filing inaccurate financial affidavits. Any temporary award is without prejudice to the final judgment.

Effective: 2016

Contested divorce trials must be bifurcated — the issue of whether irreconcilable differences have caused the irretrievable breakdown of the marriage is tried first, regardless of whether that issue is contested. Only after the court makes a finding on grounds does the trial proceed to property, support, and parenting issues.

Effective: 2016

The Illinois Domestic Violence Act (separate from the IMDMA) allows victims to obtain emergency, interim, or plenary orders of protection. These orders can prohibit the abuser from the shared home, grant temporary parenting time, and require the abuser to stay away from the victim. Violation of an order of protection is a criminal offense. Orders can be obtained as part of a divorce case or independently.

Effective: 1986

Illinois enacted the Collaborative Process Act in 2018, providing a formal framework for resolving divorce and family law disputes without going to court. Both parties sign a participation agreement committing to negotiate in good faith and agreeing that if the process fails, both attorneys must withdraw from the case. Filing the agreement operates as a stay of any pending court proceedings.

Effective: 2018

Prenuptial agreements in Illinois must be in writing, signed by both parties, and entered into voluntarily. They may cover property division, maintenance waivers, and financial rights but cannot predetermine child support, parenting time, or parental responsibilities. A prenup is unenforceable if the court finds it unconscionable, was signed under duress, or one party failed to disclose material assets or income.

Effective: 1990

Either spouse may request restoration of a former name as part of the dissolution proceedings. The court will grant the name change request as part of the divorce judgment without requiring a separate name change petition, making the process simpler and less expensive than a standalone name change proceeding.

Effective: 2016

As of January 2025, courts may still impute income to an unemployed or underemployed parent for child support purposes, but new safeguards apply. The court must conduct an evidentiary hearing (or the parties must agree) before imputing income, and the court must make specific written findings identifying the basis for imputation. This prevents arbitrary income assumptions.

Effective: 2025