Quest Diagnostics reports breach exposing patient records

Quest Diagnostics has confirmed that an unauthorised party accessed a system used by healthcare providers to order laboratory tests and view results, affecting personal information and patient records. The incident targets the Quanum Lab Services Manager (LSM) platform, which allows clinicians to order tests, view results, review historical trends, and order supplies.

Quest reported the breach began with unauthorised access identified on 21 October 2026, and says access to the platform has been paused while it investigates. The company notes that its core business operations remain up and running. No total count of affected patients or a complete list of accessed information has been provided yet; Quest says it will notify affected patients, healthcare providers and health plans as the investigation proceeds.

The firm has stated that health information and personally identifiable information were involved, but has not specified whether this included Social Security numbers, insurance identifiers, payment details, particular test results, or account passwords.

In its initial guidance, Quest says notification letters will be sent to affected patients once the investigation is complete, outlining available resources such as credit and identity monitoring. Patients are advised to read such letters carefully and to consult Quest’s breach notice FAQs for updates. The article notes practical steps for patients and emphasises that medical identity theft can affect care, potentially introducing incorrect information into health records.

It also lists general precautionary measures such as verifying unexpected breach communications independently, reviewing medical bills and credit reports, and pursuing appropriate remedies if identity theft is suspected.