Quest Diagnostics confirms data breach affecting patient records

Quest Diagnostics has confirmed that an unauthorized party accessed its Quanum Lab Services Manager (LSM) platform. The breach, discovered on October 21, involves a system used by healthcare providers to order laboratory tests, view results, and review historical trends.

The company stated that the intrusion affected personal information and patient records, including health information and personally identifiable information. While Quest has not yet specified the exact types of data exposed—such as Social Security numbers or insurance identifiers—or the total number of affected individuals, it has notified federal regulators and law enforcement.

Quest Diagnostics, which serves approximately one-third of U.S. adults annually, noted that its core business operations and direct laboratory system connections remain functional. The company has paused access to the compromised platform while investigations continue. Affected patients and healthcare providers will be notified via mail once the investigation is complete, with resources such as credit and identity monitoring to be offered.