Illinois medical malpractice claims are governed by a two-year discovery rule and a four-year statute of repose that strictly limit when actions may be filed. These timing rules operate within a broader framework of state-specific filing deadlines and limitations periods that vary significantly across jurisdictions, shaping how malpractice claims are evaluated and brought nationwide.
This article explains Illinois’s medical malpractice statute of limitations framework, including how the discovery rule operates, the effect of the four-year statute of repose, recognized tolling exceptions, and recent judicial interpretations that influence when claims must be filed. It also clarifies how Illinois courts distinguish between professional negligence and ordinary negligence for timing purposes, and how these rules apply in practice.
Core Rules for the Medical Malpractice Statute of Limitations in Illinois
Illinois medical malpractice claims are governed by 735 ILCS 5/13-212, which establishes a dual-deadline framework combining a discovery-based statute of limitations with an absolute statute of repose. The statute applies to “healing art malpractice” actions arising from diagnosis, treatment, or care provided by licensed healthcare professionals.
Two-Year Discovery Rule
Medical malpractice actions must be filed within two years of the date the plaintiff knew, or reasonably should have known, both:
- An injury occurred.
- The injury was wrongfully caused by medical negligence.
The Illinois Supreme Court in Moon v. Rhode (2016 IL 119572) confirmed that discovery requires dual knowledge. Awareness of an adverse medical outcome alone is insufficient; the limitations period begins only when the plaintiff has reason to connect the injury to negligent medical care.
Four-Year Statute of Repose
Illinois also imposes a four-year statute of repose measured from the date of the negligent act or omission. This outer deadline operates independently of discovery and bars claims filed more than four years after the alleged malpractice occurred.
The repose period cannot be extended by delayed discovery. When an injury is discovered late in the four-year window, the plaintiff must file within whatever time remains before the repose deadline expires, even if that period is shorter than two years.
These timing rules operate independently of Illinois-specific damage limitations, which affect recoverable amounts but do not alter the timing of when malpractice claims must be filed.
Tolling Exceptions That Affect the Medical Malpractice Statute of Limitations in Illinois
Illinois recognizes four primary tolling exceptions, with a restrictive judicial interpretation that imposes substantial burdens of proof on plaintiffs seeking to extend filing deadlines.
1. Minority Exception
For minors under age 8, the statute does not begin to run until the minor reaches age 8, though the general 4-year statute of repose still applies. No action may be brought more than 8 years after the act or omission, and in no event after the person's 22nd birthday.
2. Mental Incapacity Tolling
Legal disability tolls the discovery period during proven incapacity that prevents understanding legal rights. Courts require clear medical evidence that mental incapacity rendered the person incapable of understanding their legal rights or managing their affairs.
3. Fraudulent Concealment
Fraudulent concealment can toll the filing deadline under 735 ILCS 5/13-215, extending the time to bring an action by 5 years from the date of discovery of the concealment. Courts require affirmative acts by defendants specifically calculated to conceal the cause of action.
4. Foreign Object Exception
Claims involving foreign objects unintentionally left during medical procedures receive extended protection for surgical sponges, towels, instruments, or medical devices left unintentionally during surgery. Properly implanted medical devices do not qualify for this exception.
How Illinois Courts Interpret Medical Malpractice Statute of Limitations Rules
Illinois courts consistently apply a narrow construction to timing exceptions while strictly enforcing absolute repose deadlines.
Moon v. Rhode (2016) — Discovery Rule Timing
In Moon v. Rhode (2016 IL 119572), the Illinois Supreme Court clarified that the medical malpractice statute of limitations does not begin to run upon mere awareness of an adverse medical outcome. Instead, the limitations period starts only when the plaintiff knows or reasonably should know both that an injury occurred and that it was wrongfully caused by medical negligence.
The court emphasized that discovery requires more than suspicion or dissatisfaction with treatment. Absent facts connecting the injury to negligent care, summary judgment on statute of limitations grounds is inappropriate.
Bruso v. Alexian Brothers Hospital — Statute of Repose Application
In Bruso v. Alexian Brothers Hospital (1993), the Illinois Supreme Court held that the four-year statute of repose in medical malpractice cases operates as an absolute bar, regardless of when the injury is discovered. Claims filed after the repose period are time-barred even if the plaintiff could not reasonably have discovered the malpractice earlier.
The decision confirms that the discovery rule cannot extend claims beyond the repose deadline. When discovery occurs late, plaintiffs must file within the remaining time before the four-year cutoff expires.
Recent Updates to Illinois Medical Malpractice Statute of Limitations Laws in Illinois
As of 2026, the core Illinois medical malpractice statute of limitations framework remains unchanged from recent years. The two-year discovery rule and four-year statute of repose under 735 ILCS 5/13-212 continue to govern filing deadlines without modification. No legislative amendments have altered the general medical malpractice timing requirements.
Illinois courts continue to refine the application of the dual knowledge discovery standard established in Moon v. Rhode, with appellate courts addressing fact-specific questions about when plaintiffs reasonably should have known of wrongful causation. Recent case law emphasizes objective, reasonable-person standards rather than subjective claims of ignorance when determining discovery timing.
Legislative proposals introduced in recent sessions have addressed medical malpractice reform more broadly, including certificate-of-merit requirements and expert-witness qualifications, but none have modified the fundamental statute-of-limitations structure. The General Assembly has maintained the balance between plaintiff access to courts and defendant protection from stale claims through the existing two-year discovery rule and four-year repose framework.
Local court rules govern filing and case management practices after a complaint is filed, but do not alter Illinois’s statute of limitations or statute of repose deadlines.
Meeting Medical Malpractice Filing Deadlines in Illinois
Illinois medical malpractice filing deadlines are governed by the interaction between the two-year discovery rule and the four-year statute of repose. Claims must be filed within two years of when the injury was discovered or reasonably should have been discovered, but no later than four years after the negligent act or omission, unless a narrow statutory exception applies.
Compliance depends on accurate identification of treatment timelines, injury discovery points, and supporting medical records. Legal AI tools support this work by organizing records, building defensible chronologies, and helping firms track statutory deadlines tied to case facts.
Explore Tavrn’s legal technology solutions.
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