What is Illinois’s ordinary four-year medical malpractice act-based period?

Identify the covered Illinois-licensed defendant and patient-care injury or death claim.

Establish the alleged causative act, omission or occurrence date from the relevant record.

Establish the separate earliest knowledge or written-notice event and compare its two-year component.

1. Identify the covered Illinois-licensed defendant and patient-care injury or death claim.
2. Count four calendar years after the alleged causative act, omission or occurrence. Discovery does not automatically restart this component. The separate two-year count and the applicable statutory branches remain necessary.
3. Check the final weekend, statutory holiday and the proper court’s actual calendar.
4. Commence the action within the applicable combined periods and preserve the relevant treatment, act, knowledge and notice records. Complete the separately applicable affidavit and report duties.

Section 1.11 excludes a final Saturday, Sunday or statutory holiday and consecutive excluded days. Section 17(a) of the Promissory Note and Bank Holiday Act includes Pulaski Day, Good Friday and the general election for members of the House of Representatives. Check proclamations, the proper court’s actual calendar and clerk access separately. The bundled Illinois calendar covers 2026 and 2027.

Fictitious example

Use the ordinary act-based component for a covered adult claim with no applicable disability or statutory exception. It does not replace the potentially earlier discovery deadline. Fictitious statutory event, independently established under the precise scope stated in this guide. Use the ordinary act-based component for a covered adult claim with no applicable disability or statutory exception. It does not replace the potentially earlier discovery deadline.

Fictitious ordinary adult patient-care claim with a separately established later discovery component. This computes the four-year component and does not determine all commencement limits.

An act date is distinct from a discovery date

Subsection (a) measures four years from the causative act, omission or occurrence, while its two years use the earliest knowledge or written notice. Identify both chronologies.

An earlier discovery boundary remains relevant

A later four-year output does not permit filing beyond the otherwise applicable two-year discovery boundary. This preset calculates a component, not their automatic comparison.

Children have a different stated scheme

Subsection (b) addresses claims accruing while under eighteen with an eight-year act-based limit and twenty-second-birthday boundary. Its historical transition also requires the applicable edition.

Disability timing matters

Subsection (c) addresses disability other than minority existing at accrual. Subsection (d) addresses disability occurring later and expressly does not invalidate repose. Do not treat every disability as restarting four years.

Express statutory exceptions require individual review

Subsection (a) excepts Sections 13-215 and 13-215.1. Establish qualifying concealment or the specific fertility-fraud statutory claim and chronology.

The report is a separate procedural duty

Section 2-622 requires the stated affidavit and professional report. Its qualifying report deferral does not automatically add ninety days to the ordinary four-year commencement component.

• This calculation does not determine whether relief is available or whether the facts satisfy the statute.
• A current statutory edition does not establish the law for every historical claim. Preserve the applicable edition and actual orders.

• Identify the covered Illinois-licensed defendant and patient-care injury or death claim.
• Establish the alleged causative act, omission or occurrence date from the relevant record.
• Establish the separate earliest knowledge or written-notice event and compare its two-year component.
• Subsection (a) measures four years from the causative act, omission or occurrence, while its two years use the earliest knowledge or written notice. Identify both chronologies.
• A later four-year output does not permit filing beyond the otherwise applicable two-year discovery boundary. This preset calculates a component, not their automatic comparison.
• Subsection (b) addresses claims accruing while under eighteen with an eight-year act-based limit and twenty-second-birthday boundary. Its historical transition also requires the applicable edition.
• Subsection (c) addresses disability other than minority existing at accrual. Subsection (d) addresses disability occurring later and expressly does not invalidate repose. Do not treat every disability as restarting four years.
• Subsection (a) excepts Sections 13-215 and 13-215.1. Establish qualifying concealment or the specific fertility-fraud statutory claim and chronology.
• Section 2-622 requires the stated affidavit and professional report. Its qualifying report deferral does not automatically add ninety days to the ordinary four-year commencement component.
• Commence the action within the applicable combined periods and preserve the relevant treatment, act, knowledge and notice records. Complete the separately applicable affidavit and report duties. File with the proper clerk in the required format. Rule 9 ordinarily requires civil electronic filing, subject to its exceptions and exemptions. Rule 9(f) ordinarily requires submission before midnight in the court time zone unless a statute, rule or actual order specifies a different time. A submission on a closed clerk day ordinarily receives the next open-day stamp. Preserve the actual electronic file mark, receipt and any filing-relief order. Filing and service are distinct acts.