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Regulator-posted notice

Breach notice filed by City of Hope (December 2023)

Organization named: City of Hope Provisional: identity as filed, not yet matched to the directory
Type as the source lists it: Hacking/IT Incident

What the sources say

HHS OCR breach portal (HIPAA breaches affecting 500 or more individuals) Primary notice

Posted on the HHS OCR breach portal (HIPAA breaches affecting 500 or more individuals) with a submission date of Dec. 12, 2023.

Organization as reported
City of Hope, CA
Entity type as reported
Healthcare Provider
Category as reported
Hacking/IT Incident
Location of information as reported
Network Server
Submission date
Dec. 12, 2023
Observed by BreachRecords
2026-10-18 16:15 UTC (revision 10278, row:1417)
Archived copy
Held in the private archive (provenance)

The covered entity (CE), City of Hope, reported that it experienced a cyber-attack that affected the protected health information (PHI) of 902,540 individuals. The PHI involved included names, dates of birth, Social Security and drivers’ license numbers, financial and health insurance information, diagnoses, and other treatment information. The CE notified HHS, affected individuals, and the media. In its mitigation efforts, the CE implemented additional administrative, technical, and security safeguards.

The source's own words, from the revision above.

Figures, per source

  • 902,540 individuals affected (total reported), as reported by the HHS OCR breach portal (HIPAA breaches affecting 500 or more individuals), source date Dec. 12, 2023, revision observed 2026-10-18.

Each figure is one source's figure with the basis that source gave. Figures from different sources are shown side by side and are not added, averaged or chosen between.

Timeline

Source dates are the dates the sources give. Observation dates are when BreachRecords recorded each revision.

  • Submission date at the HHS OCR breach portal (HIPAA breaches affecting 500 or more individuals)
  • Observed by BreachRecords (revision 10278)
  • Approved by a reviewer

Organizations linked by a reviewer

  • City of Hope Named as the covered entity Provisional: identity as filed, not yet matched to the directory Linked 2026-10-19, method provisional.

Archived evidence

  • 3dbc27dd5742e041cc1e7fe18cc669e2901fbd3b86b7007ed27948ff4d406e1f
    text/csv, 5,530,996 bytes, from the HHS OCR breach portal (HIPAA breaches affecting 500 or more individuals), retrieved 2026-10-18 16:15 UTC. Archived privately · Provenance · Source page

Records reflect source filings as of the dates shown. BreachRecords is not a regulator.

Request a correction

A record that disagrees with its source, names the wrong organization or duplicates another is corrected after review. This form is about Breach notice filed by City of Hope (December 2023). We acknowledge every request within two business days. We reply by email.

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