Quest Diagnostics has confirmed unauthorized access to its Quanum Lab Services Manager system, raising privacy concerns for patients whose records were held there. In its October 23 notice and FAQs, the company said personal information and patient records were affected, while the specific data and people involved were still being investigated.
What Quest has confirmed
Quanum LSM is used by some healthcare clients to order tests and retrieve results. Quest said it paused access after discovering the incident. Its core business operations continued, and direct laboratory and electronic medical record interfaces used by other clients were not affected.
The company said it was communicating with law enforcement and would notify patients determined to be affected. Its patient FAQ said notification letters would describe available support, including credit and identity monitoring.
What remains unclear
The notice reviewed for this report did not give a total number of affected patients or a complete list of exposed data fields. Being a Quest patient does not, by itself, establish that your records were involved. Quest also said its investigation had not linked the incident to the PHP security issue attracting attention that week.
What patients can do now
Check updates by visiting Quest’s official website directly. Treat unexpected messages offering breach compensation or asking you to verify an account with caution. Do not provide passwords or sign-in codes to someone who contacts you about the incident.
Keep any genuine notification letter: its description of the affected information matters more than a general headline. If a message concerns a test or appointment, contact your provider through a number you already trust.
For a practical response checklist, read what to do after a data breach.
Sources
Reporting checked October 26, 2026. Primary source: Quest Diagnostics incident notice and patient FAQs. This report reflects the dated notice reviewed; follow that page for subsequent updates.