Do you need to prove fault to start a divorce in Illinois? Divorce law in Illinois has changed dramatically in recent decades. For most of the state’s history, spouses seeking a divorce had to allege fault—adultery, cruelty, abandonment, or similar misconduct. That all changed with the 2016 amendments to the Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5/), which made “irreconcilable differences” the sole ground for divorce in Illinois. This reform reshaped the legal process, emotional dynamics, and privacy expectations for families navigating dissolution.
The Move from Fault to No-Fault Divorce
From as early as 1874, Illinois law listed specific fault-based justifications for divorce. Each required proof, testimony, and often public disclosure of intimate details in open court. The process was emotionally taxing and socially charged. Lawmakers, concerned about divorce’s moral implications, even imposed a mandatory one-year waiting period in 1905 before remarriage could occur—two years if adultery was involved.
By the late twentieth century, however, the state recognized that requiring spouses to prove fault often did more harm than good. In 1984, “irreconcilable differences” was introduced as an optional, no-fault ground alongside traditional causes. More than thirty years later, in 2016, the Illinois legislature amended the IMDMA to fully abolish fault-based divorce under Public Act 99-90.
What Are “Irreconcilable Differences”?
Under 750 ILCS 5/401(a), a court may dissolve a marriage when irreconcilable differences have caused an irretrievable breakdown in the relationship, efforts at reconciliation have failed, and future attempts would not be in the best interests of the family.[2] There is no longer a need to prove wrongdoing by either spouse.
If both parties consent to the divorce, no waiting period applies. If one spouse contests it, the law presumes irreconcilable differences after six months of living separately.
The result is a simpler, less adversarial process—one that acknowledges that marriages can end without either party being “at fault.”
Impacts on Illinois Families
The transition to no-fault divorce has had several practical implications:
- Reduced conflict: Couples can dissolve their marriage without public accusations or moral arguments.
- Efficiency: Courts handle more cases through settlement and consent, reducing trial time and legal costs.
- Privacy: Families avoid airing sensitive personal issues in open proceedings.
- Focus on resolution: Attorneys and judges can emphasize financial fairness and child welfare, rather than proving fault.
Today, Illinois law treats marital breakdowns as personal, private matters handled in a respectful, pragmatic manner. The 2016 reforms continue that evolution, emphasizing cooperation and shared parenting responsibilities over blame and punishment.
The shift to purely no-fault divorce underscores a profound change in social and legal attitudes toward marriage. As Illinois courts interpret the IMDMA, the focus remains clear: protecting the interests of children, promoting fairness, and recognizing that sometimes marriages end simply because they no longer work. Questions about divorce in Illinois. Give Michael Roe a call or contact him through the Contact Page for an initial consultation.