Illinois Family Laws

Filing fees vary by county. Cook County charges approximately $388 for a petition. Fee waivers are available.

At least one spouse must have been an Illinois resident for at least 90 days before filing.

Courts allocate parental responsibilities based on the best interests of the child. Both parents are presumed fit. Factors include: each parent's wishes, the child's wishes, time spent performing caretaking functions, the child's relationships and adjustment, and any history of violence or abuse.

Marital property is divided in "just proportions" considering duration of marriage, each party's contributions, dissipation of assets, economic circumstances, and custodial provisions. Illinois is NOT a community property state.

Amount: 33.33% of payor's net income minus 25% of payee's net income (cap: payee cannot exceed 40% of combined net income). Applies when combined gross income is under $500,000. Duration multiplied by marriage length: 20% for 0–5 years, 40% for 5–10, 60% for 10–15, 80% for 15–20, court discretion for 20+.

Illinois uses the income shares model (adopted 2017). Both parents' net incomes are combined and the obligation is allocated proportionally based on a state schedule. Factors include number of children, overnights, and extraordinary expenses.

Three types: Emergency (up to 21 days), Interim (up to 30 days), and Plenary (up to 2 years). Abuse includes physical abuse, harassment, intimidation of a dependent, interference with personal liberty, and willful deprivation.