Quest Diagnostics (Quanum LSM) data breach
Was I affected?
Quest Diagnostics (Quanum LSM) confirmed a breach affecting an undisclosed number of people, exposing medical information. You may be affected if your doctor or clinic ordered Quest lab tests or viewed your results through Quest's Quanum LSM portal.
| Announced | Oct 22, 2026 |
|---|---|
| When it happened | Discovered October 21, 2026 |
| Country | United States |
| Data exposed | Medical information |
| Status | Confirmed by the company or a regulator filing |
What happened
Quest Diagnostics, the large U.S. lab testing company, told the SEC on October 22, 2026 that it had learned the day before of unauthorized access to its Quanum Lab Services Manager (LSM) system, which some clients use to place test orders and receive and look up results. Quest said it believes an unauthorized party accessed certain patient records, but the full scope is still under investigation. It has not said how many patients are affected or which data fields were exposed. Quest paused the Quanum LSM system and some related tools while it investigated, and says direct lab interfaces and electronic medical record connections were not affected.
What should I do?
- Watch your mail for a notice letter from Quest and follow its instructions.
- Be cautious of calls, emails or texts about lab results, unpaid lab bills or breach 'settlements'; contact Quest or your doctor using numbers you already have.
- Review insurer explanation-of-benefits statements for tests you didn't have.
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Sources
- Quest Diagnostics Incorporated Form 8-K (Item 8.01) · U.S. Securities and Exchange Commission · regulator
- Quest Diagnostics confirms data breach exposed patient records · BleepingComputer · news