Family Law Laws in Illinois

Family Law Law in Illinois: Overview

Illinois family law is governed by the Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5). Illinois became a purely no-fault divorce state in 2016 when it eliminated all fault-based grounds, making irreconcilable differences the sole ground for dissolution. The state follows equitable distribution for property division and uses the terms "allocation of parental responsibilities" and "parenting time" instead of custody and visitation. Illinois has a statutory formula for calculating maintenance (alimony) based on the parties' incomes and the duration of the marriage, and uses the income shares model for child support. The state requires a 90-day residency period before filing. Illinois is notable for its detailed statutory maintenance formula, which provides predictability in support calculations, and for its comprehensive overhaul of family law in recent years.

Key Statutes & Deadlines

Statutory Maintenance Formula

Illinois has a detailed statutory formula for calculating maintenance under 750 ILCS 5/504(b-1). When the combined gross income of both parties is less than $500,000, the guideline amount is calculated as 33.33% of the payor's net income minus 25% of the payee's net income. The total of the maintenance payment and the payee's net income cannot exceed 40% of the combined net income. The duration of maintenance is determined by multiplying the length of the marriage by a statutory factor that increases with the marriage length: 0.20 for marriages of 0-5 years, gradually increasing to 0.80 for marriages of 15-20 years, and permanent (reviewable) maintenance for marriages of 20 years or more. Courts may deviate from the guidelines based on specific statutory factors.

Allocation of Parental Responsibilities

Illinois replaced the terms "custody" and "visitation" with "allocation of parental responsibilities" and "parenting time" in its 2016 family law reform. Under 750 ILCS 5/602.7, the court allocates significant decision-making responsibilities (education, health, religion, extracurricular activities) based on the best interests of the child, considering factors including the wishes of the parents and child, the child's adjustment to home, school, and community, the mental and physical health of all individuals, each parent's willingness to facilitate a relationship with the other parent, any history of violence or abuse, and the distance between the parents' residences. Parenting time is allocated under a separate set of factors focused on the child's best interests.

Equitable Distribution and Dissipation

Illinois divides marital property equitably, considering factors including each spouse's contribution to the acquisition, preservation, or increase in value of marital property, the dissipation of marital property by either spouse, the value of each spouse's non-marital property, the duration of the marriage, the relevant economic circumstances of each spouse, any prenuptial agreement, the age and health of the parties, and the tax consequences of the property division. Illinois has developed significant case law on "dissipation" of marital assets, which occurs when one spouse uses marital property for a purpose unrelated to the marriage while the marriage is undergoing an irretrievable breakdown. A claim of dissipation shifts the burden to the accused spouse to prove the expenditure was for a legitimate marital purpose.

Illinois Court System

Family law cases in Illinois are heard by the Circuit Courts, which are the state's trial courts of general jurisdiction. Illinois has 24 judicial circuits, with the Circuit Court of Cook County (Chicago) being the largest. Many circuits have dedicated domestic relations divisions with judges assigned to family law matters. Illinois requires mediation in contested custody (parental responsibilities) cases in many circuits. The state utilizes guardians ad litem, child representatives, and custody evaluators in contested parenting cases. Appeals from Circuit Court family law decisions go to the Illinois Appellate Court (organized into five appellate districts) and may be further reviewed by the Illinois Supreme Court. Illinois has also been a leader in developing collaborative divorce practices and offers parenting coordination services for high-conflict cases.

Damages & Penalties

Illinois courts divide marital property equitably, considering statutory factors including contributions, dissipation, duration of marriage, and each party's economic circumstances. Maintenance follows the statutory formula for combined incomes under $500,000, with the duration tied to the length of the marriage through multiplier factors. For marriages of 20 years or more, the court may award permanent maintenance subject to review. Child support is calculated using the income shares model, considering both parents' net incomes, the number of children, health insurance costs, childcare expenses, and the parenting time arrangement. The guidelines include adjustments for shared parenting time. Enforcement of support orders includes income withholding, tax refund intercepts, license suspension, contempt of court, passport denial, and criminal prosecution for willful nonpayment. Illinois also allows for interest on past-due support and may require the posting of security for future payments. Modification of maintenance or child support requires a showing of a substantial change in circumstances.

Recent Legislative Changes

Illinois completed a major overhaul of its family law in 2016, eliminating fault-based divorce, replacing custody terminology with parental responsibilities, and adopting the income shares model for child support (replacing the percentage of income model). The state has continued to refine its maintenance formula and improve access to family court services.

Frequently Asked Questions