Illinois Divorce Laws: Residency, Alimony, and Custody Explained

Divorce is never easy, but understanding your rights under state law can make the process more manageable. If you’re considering filing for divorce in Illinois, it’s important to know the legal requirements related to residency, spousal support (alimony), and child custody.

This guide offers a clear overview of key Illinois divorce laws in 2025 to help you make informed decisions about your future.

Residency Requirements for Divorce in Illinois

Before filing for divorce in Illinois, you or your spouse must meet the residency requirement.

Key Requirements:

• One spouse must live in Illinois for at least 90 days before filing.
• You must file in the county where either spouse resides.

If children are involved, they must have lived in Illinois for at least six months before the court can rule on custody matters.

Grounds for Divorce in Illinois

Illinois is a pure no-fault divorce state, meaning you don’t need to prove wrongdoing such as adultery or abuse.

Legal Ground for Divorce:

• Irreconcilable differences that have caused the breakdown of the marriage with no reasonable chance of reconciliation.

If both spouses agree, the court can proceed quickly. If one spouse contests, the court may require the couple to live apart for at least six months as proof of irreconcilable differences.

Alimony (Spousal Maintenance) in Illinois

Spousal support in Illinois is referred to as maintenance. It may be temporary, rehabilitative, or long-term depending on the circumstances.

How It’s Determined:

Illinois uses a formula based on both spouses’ income and the length of the marriage for couples with a combined gross income below $500,000.

Formula Example:

• 33.3% of the payor’s net income – 25% of the recipient’s net income
• The resulting amount cannot exceed 40% of the combined net income

Factors the Court Considers:

• Duration of the marriage
• Financial needs of both spouses
• Earning capacity and education
• Age and health of each party
• Standard of living during the marriage
• Contributions to homemaking or career development

Judges may deviate from the formula if fairness requires it.

Child Custody in Illinois

Illinois uses the term “allocation of parental responsibilities” instead of custody. The goal is to prioritize the best interests of the child, not parental preference.

Components of Custody:

• Decision-making authority (education, healthcare, religion, extracurriculars)
• Parenting time (formerly known as physical custody or visitation)

Factors Considered:

• Child’s relationship with each parent
• Adjustment to home, school, and community
• Mental and physical health of all parties
• History of domestic violence or abuse
• Willingness of each parent to support the child’s relationship with the other parent

Shared parenting is encouraged when both parents are cooperative and capable.

Child Support in Illinois

Child support is determined using the Income Shares Model, which accounts for:

• Both parents’ incomes
• Number of children
• Parenting time percentages
• Expenses like healthcare and daycare

The support obligation is calculated from tables published by the Illinois Department of Healthcare and Family Services.

Property Division in Illinois

Illinois is an equitable distribution state. This means marital property is divided fairly, though not always equally.

Marital Property Includes:

• Assets and debts acquired during the marriage
• Joint bank accounts, real estate, vehicles, retirement plans

Excluded (Non-Marital) Property:

• Assets owned before marriage
• Gifts and inheritances to one spouse
• Assets excluded by a prenuptial agreement

The court considers:

• Duration of marriage
• Contributions by each spouse (financial and non-financial)
• Future earning potential
• Custody and housing needs

Final Thoughts

Whether you’re planning to file or responding to a divorce in Illinois, knowing your rights is essential. From residency rules to alimony and custody, Illinois law provides a structured but flexible framework.

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