Breach filing
ArchivedOSF HealthCare System: 53,907 individuals, Oct 2021.
OSF HealthCare System reported a breach of unsecured protected health information to the HHS Office for Civil Rights on 1 October 2021. The filing records the organisation as a healthcare provider in Illinois and lists 53,907 individuals affected, which makes it the 57th largest of the 358 Illinois filings on the register and the 124th largest of the 715 filings submitted nationally in 2021. Among the 41 Illinois filings made in 2021 it ranks 9th.
Individuals affected
53,907
As reported to HHS
Modelled cost (IBM 2025)
$8.63M
Method shown, not disclosed
Rank in IL
57th
of 358 Illinois filings
Rank in 2021
124th
of 715 filings nationally
Section F.1 / The filing
As posted by HHS OCR
Every value below is the portal's own field for this filing, plus its rank within the register.
- Covered entity type
- Healthcare Provider
- Individuals affected
- 53,907
- Breach submission date
- 1 October 2021
- Submission year
- 2021
- Type of breach
- Hacking/IT Incident
- Location of breached information
- Network Server
- Business associate present
- No
- State
- Illinois (IL)
- Portal status
- listed in the HHS OCR breach portal archive
- Rank in Illinois by size
- 57th of 358
- Rank in 2021 nationally
- 124th of 715
- Illinois median filing
- 3,403 individuals
- Register id (derived)
- IL-20211001-osf-healthcare-system
Section F.2 / In context
Where this filing sits in Illinois and in 2021
OCR classifies the incident as a hacking or IT incident, with the breached information held in a network server. Hacking/IT Incident is the type recorded on 201 of the 358 Illinois filings (56%) and on 76% of all filings submitted in 2021. Network Server appears on 43% of Illinois filings.
No business associate is recorded on the filing; 34% of Illinois filings do involve one. At 53,907 individuals the breach is 16 times the Illinois median filing of 3,403 and 13 times the national median of 4,000 across all 7,884 filings. It sits in the 10,000 to 99,999 band, which holds 1,938 filings.
As of 28 August 2026 the case is listed in the HHS OCR breach portal archive. OCR's closing summary of the case is reproduced in full below.
Illinois's breach notification statute (815 ILCS 530) requires notice to affected residents in the most expedient time possible and without unreasonable delay. Its attorney general threshold: more than 500 Illinois residents (private collectors); 250 for state agencies. The HIPAA Breach Notification Rule ran alongside it: notice to affected individuals and to HHS without unreasonable delay and no later than 60 days after discovery, which is the clock that put this filing on the portal.
Multiplying 53,907 individuals by IBM's $160 customer-PII cost per record (Cost of a Data Breach 2025, the figure the site's calculator uses) gives a modelled $8.63M; the 2026 edition's $192 gives $10.4M. Both are modelled estimates with the method shown, not costs disclosed by OSF HealthCare System. For scale, IBM's 2026 average cost of a healthcare breach is $6.64M, so this filing models at 1.6 times the sector average.
Section F.3 / OCR closing summary
The portal's archived description, in full
Written by the Office for Civil Rights when the case was closed and reproduced verbatim from the HHS export.
The U.S. Department of Health and Human Services (HHS), Office for Civil Rights (OCR) today announced a settlement with OSF Healthcare System and its Affiliated Covered Entities (OSF), concerning potential violations of the Health Insurance Portability and Accountability Act of 1996 (HIPAA) Privacy, Security, and Breach Notification Rules. OSF is headquartered in Illinois and has providers located in Illinois and Michigan.
OCR enforces the HIPAA Privacy, Security, and Breach Notification Rules , which set forth the requirements that covered entities (health plans, health care clearinghouses, and most health care providers), and business associates must follow to protect the privacy and security of PHI.
The settlement resolves an investigation that OCR initiated after OSF filed a breach report in October 2021. In April of 2021, OSF discovered that its files had been infected with the "Nephilim" variant of ransomware. The PHI of 53,907 individuals was exfiltrated by the threat actor. Affected PHI included driver's license numbers, diagnosis and treatment information, prescription information, medical record numbers, provider names, dates of services, financial account information, and health insurance information. OCR found that OSF had potentially violated provisions of the Privacy, Security and Breach Notification Rules, including:
· Failing to conduct an accurate and thorough risk analysis of the potential risks and vulnerabilities to the ePHI held by OSF;
· Impermissibly disclosing the PHI of 53,907 individuals;
· Failing to provide timely breach notification to affected individuals; and
· Failing to provide timely breach notification to the Secretary of HHS.
Under the terms of the resolution agreement, OSF agreed to implement a corrective action plan that OCR will monitor for two years and paid $552,250 to OCR. Under the corrective action plan, OSF has committed to taking steps to ensure compliance with the HIPAA Rules and protect the security of ePHI, including:
· Conduct an accurate and thorough risk analysis to determine the potential risks and vulnerabilities to the confidentiality, integrity, and availability of its ePHI; and
· Develop and implement a risk management plan to address and mitigate security risks and vulnerabilities identified in its risk analysis.
The resolution agreement and corrective action plan may be found here.
OCR recommends that regulated entities, including health care providers, health plans, health care clearinghouses, and business associates take the following steps to mitigate or prevent cyber-threats:
· Identify where ePHI is located in the organization, including how ePHI enters, flows through, and leaves the organization's information systems.
· Periodically conduct, and update as needed, a risk analysis and develop and implement a risk management plan to address identified risks and vulnerabilities to the confidentiality, integrity, and availability of ePHI.
· Ensure audit controls are in place to record and examine information system activity.
· Implement regular review of information system activity.
· Utilize mechanisms to authenticate information to ensure only authorized users are accessing ePHI.
· Encrypt ePHI in transit and at rest to guard against unauthorized access to ePHI when appropriate.
· Incorporate lessons learned from incidents into the organization's overall security management process.
· Provide workforce members with regular HIPAA training that is specific to the organization and to the workforce members' respective job duties.
Section F.5 / Modelled cost
53,907 individuals through IBM's per-record figures
Modelled cost / method shown, not a disclosed cost
ModelledIBM 2025 customer PII, $160 per record
$8.63M
53,907 x $160
IBM 2026 customer PII, $192 per record
$10.4M
53,907 x $192
Method: individuals affected, as reported by OSF HealthCare System to HHS, multiplied by IBM's customer-PII cost per record (Cost of a Data Breach 2025 Figure 6 and the 2026 edition). No cost has been disclosed by the entity for this filing; the figure is a planning estimate, not a fact about the breach. IBM's per-record figures come from mid-volume breaches and IBM cautions against applying them to breaches involving millions of records; the site's per-record page explains where the multiplication holds and where it breaks down.
Context: IBM's average cost of a healthcare breach is $6.64M in the 2026 report ($7.42M in 2025); the global average across all sectors was $4.44M in 2025.
Cost per record: method and limits / Healthcare breach cost, IBM 2026
Section F.6 / Notification clock
Illinois statute and the HIPAA rule
State notification statute
Illinois: 815 ILCS 530
Personal Information Protection Act (PIPA)
- Notice to individuals
- In the most expedient time possible and without unreasonable delay
- Attorney general threshold
- More than 500 Illinois residents (private collectors); 250 for state agencies (Within 45 days of discovery or at the time of consumer notice, whichever is sooner)
- Private right of action
- No: No direct PROA under PIPA; claims may run through the Consumer Fraud Act, and BIPA covers biometric data separately
- Penalty
- Up to $50,000 per violation under the Consumer Fraud Act; restitution prioritized over penalties
The HIPAA Breach Notification Rule runs alongside the state statute: notice to affected individuals and to HHS without unreasonable delay and no later than 60 days after discovery.
Section F.7 / Peer filings
Illinois filings closest in size
Neighbours by size rank among Illinois filings in 2021, topped up from other years where 2021 has too few. Filings of 10,000 or more link to their own page.
| Covered entity | Type | Individuals | Submitted | Breach type | Location | BA |
|---|---|---|---|---|---|---|
| Bansley and Kiener, LLP | Business Associate | 70,941 | 3 Dec 2021 | |||
| Mobile Anesthesiologists | Healthcare Provider | 65,403 | 10 Mar 2021 | |||
| Navistar, Inc. Health Plan and the Navistar, Inc. Retiree Health Benefit and Life Insurance Plan | Health Plan | 49,000 | 24 Sep 2021 | |||
| Consociate Health | Business Associate | 48,583 | 3 Nov 2021 |
Index / Companion schedules
13 HHS breach register
→Hub: every filing, by state, year and entity.
04 Biggest breaches
→Mega-breaches with primary-source cost figures.
Industry / Healthcare
→IBM 2026: $6.64M average, 13 years at #1.
Regulation / HIPAA penalties
→OCR enforcement tiers and the 60-day rule.
11 50-state laws
→Deadline, AG threshold and penalties per state.
Cost / Per record
→Where the per-record model is reliable.
Provenance
Source: U.S. Department of Health and Human Services, Office for Civil Rights, Breach Portal (breaches affecting 500 or more individuals), retrieved 2026-08-28. Public domain. Individuals affected and dates as reported by the covered entity.
Portal: ocrportal.hhs.gov breach report. Statutory basis: HITECH Act section 13402(e)(4): the Secretary must post a list of breaches of unsecured protected health information affecting 500 or more individuals. Breaches affecting fewer than 500 individuals are reported to OCR annually and are not posted, so they are not on this register. Status wording follows the portal's two tabs ("Cases Currently Under Investigation" and "Archive") as of 28 August 2026; a filing moves to the archive when OCR closes the case. Modelled costs on this site are a method applied to the reported count, using IBM Cost of a Data Breach per-record figures, and are never a cost disclosed by the entity. This row: hhs-breach-archive__2026-08-28.csv, export row 2923.
Corrections: if you represent a listed entity and the portal row has been amended, email [email protected] with the portal entry and we will re-pull the export.