How to File for Divorce in Cook County and Illinois
To initiate an Illinois divorce under the Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5/), at least one spouse must meet the 90-day residency requirement. Illinois is a pure no-fault state, meaning petitioners only cite irreconcilable differences. If spouses live separately for 6 months (180 days), the court maintains a statutory presumption of an irretrievable breakdown. The process begins by filing a Petition for Dissolution of Marriage in the Illinois Circuit Court, paying a county-specific filing fee (averaging $337 to $388 in Cook County), and serving the respondent. Once served, the Respondent has 30 days to file an Appearance and Answer to avoid a default judgment.
Illinois Residency Requirements for Dissolution
The Illinois residency requirement stipulates that at least one spouse must establish 90 days of continuous residency before filing a divorce petition. This 90-day jurisdictional window allows the Illinois Circuit Court to exercise subject-matter jurisdiction over the case. Acceptable proof of residency includes an Illinois-issued driver’s license or state ID. Filing before the 90-day period expires will result in a mandatory dismissal for lack of jurisdiction.
Filing the Petition for Dissolution of Marriage
The Illinois divorce filing process requires submitting a Petition for Dissolution of Marriage to the Circuit Court Clerk. While filing fees vary, most Illinois counties require a payment between $300 and $450.
Required Illinois Court Documents include:
- Petition for Dissolution of Marriage: The primary pleading initiating the case.
- Uniform Financial Affidavit: A sworn statement disclosing all 750 ILCS 5/503 marital and non-marital assets.
Service of Process in Illinois Divorce Cases
Illinois service of process is the mandate by which the Petitioner formally notifies the Respondent. Illinois law recognizes three methods:
- Personal Service: A Licensed Process Server or County Sheriff delivers papers directly.
- Substitute Service: Papers are left with a competent resident at least 13 years of age at the Respondent’s home.
- Service by Publication: Requires a 3-week public notice in a local newspaper if a diligent search fails to locate the Respondent.
Responding to an Illinois Divorce Summons
The Illinois 30-day response window begins the moment the Respondent is served. Failure to file an Appearance within these 30 days allows the Petitioner to move for a Default Judgment. An Illinois family law attorney can prepare the Appearance and Answer to ensure the Respondent’s rights to 750 ILCS 5/503 asset division are protected.
Discovery Phase and Asset Disclosure
The Illinois discovery phase is a court-supervised exchange of financial data. Under Illinois Supreme Court Rule 214, spouses must disclose all bank statements, tax returns, and pay stubs. Discovery tools used by Chicago divorce attorneys include:
- Interrogatories: Written questions regarding 750 ILCS 5/503 assets.
- Depositions: Oral examinations conducted under oath.
Mediation and ADR under the Illinois Uniform Mediation Act
The Illinois Uniform Mediation Act (710 ILCS 35/) governs alternative dispute resolution. Illinois mediation typically resolves cases in 4 to 8 weeks, significantly faster than the 12–24 month timeline required for a contested trial in Cook County.
Illinois Trial and Final Judgment Standards
The Illinois Circuit Court judge resolves contested issues during a trial based on specific statutory formulas:
- Child Support: Calculated via the Illinois Income Shares Model (750 ILCS 5/505).
- Maintenance: Determined by the 750 ILCS 5/504 formula based on gross income and marriage duration.
- Property: Divided via Equitable Distribution (750 ILCS 5/503), not a strict 50/50 split.
Finalizing the Illinois Divorce Decree
The Illinois Judgment for Dissolution of Marriage is the final court order signed by a judge. To modify this judgment, a party must prove a substantial change in circumstances under 750 ILCS 5/510. Specifically, parenting responsibility orders cannot be modified for 2 years following the judgment unless the child’s health is at immediate risk.
Post-Divorce Legal Obligations in Illinois
The Illinois Secretary of State and the Social Security Administration must be notified of any name changes post-decree. Furthermore, failing to adhere to 750 ILCS 5/505 support terms constitutes Indirect Civil Contempt under Illinois Supreme Court Rule 216, punishable by license suspension or incarceration.
Frequently Asked Questions:
How is the divorce process initiated under the Illinois Marriage and Dissolution of Marriage Act?
A petitioner initiates an Illinois divorce by filing a Petition for Dissolution of Marriage with the Circuit Court Clerk in the county where either spouse has established 90 days of continuous residency. Common jurisdictions include the Cook County, DuPage County, or Lake County Circuit Courts, each requiring a specific filing fee (typically ranging from $330 to $388).
Does 750 ILCS 5/ require a separation period before filing for divorce?
No, 750 ILCS 5/ does not mandate a physical separation period before filing a petition. However, if spouses have lived separately for 6 consecutive months (180 days), the law creates a statutory presumption of irreconcilable differences. This eliminates the legal requirement for additional testimony to prove the irretrievable breakdown of the marriage.
How do Illinois Circuit Courts divide marital property in a dissolution proceeding?
Under the 750 ILCS 5/503 equitable distribution standard, Illinois courts divide marital assets and debts fairly, though not necessarily in a 50/50 split. The court evaluates factors such as the duration of the marriage, each spouse’s economic contribution to marital property, and their respective post-divorce earning capacities to reach a just division.
What are a spouse’s legal rights to the marital home during a pending Illinois divorce?
In Illinois, both spouses maintain a legal right to occupy the marital residence throughout the proceedings. This right remains unless a judge issues a temporary order for exclusive possession or a Temporary Restraining Order (TRO), which typically requires evidence that the other spouse’s presence jeopardizes the physical or mental well-being of a party or minor children.
Can an Illinois judge establish parental responsibilities and support in the same decree?
Yes. An Illinois Circuit Court simultaneously determines allocation of parental responsibilities (750 ILCS 5/602.7) and child support within the final Judgment for Dissolution of Marriage. Support is calculated using the Illinois Income Shares Model (750 ILCS 5/505), which accounts for the combined net income of both parents and the number of overnights spent with the child.
Is dating permitted under Illinois law while a divorce case is ongoing?
While Illinois law does not explicitly prohibit dating during a pending divorce, a new relationship can impact the litigation. Specifically, if marital funds are spent on a new partner, the other spouse may file a Notice of Intent to Claim Dissipation of Marital Assets under 750 ILCS 5/503, seeking reimbursement for the spent funds.

Anna P. Krolikowska, an attorney in the Northbrook law firm of Anna P. Krolikowska P.C, focuses her practice in the area of family law. Anna realizes that importance and the impact family law matters have not only on her clients, but also on their families. From divorce and child custody to any judgment modifications, Anna considers the unique circumstances of each case to develop a course of action designed specifically to address each client’s unique needs.

