Quest Diagnostics Discloses Unauthorized Access to Quanum Lab Services Manager, Says 'Certain Patient Records' Accessed

Quanum Lab Services Manager is described in the News4JAX report as a platform where certain Quest clients can place test orders and receive or look up results. Beyond saying it believes "certain patient records" were accessed, Quest has not said how many patients or which particular records were affected; News4JAX reported that those details remain unknown while the investigation continues.

Prior Incidents and Scale

News4JAX noted that Quest has disclosed patient-record incidents before. In 2016, the company said data including lab results and contact information of about 34,000 people was exposed in an online breach. In its own 2016 notice, Quest said an unauthorized third party accessed the MyQuest by Care360 internet application on Nov. 26, 2016 and obtained protected health information of approximately 34,000 individuals, including name, date of birth, lab results and in some instances telephone numbers, and that the information did not include Social Security numbers, credit card information, insurance or other financial information. In 2019, personal information belonging to about 11.9 million Quest patients was affected after a separate hack at American Medical Collection Agency, a billing collections vendor; Quest said in a securities filing that someone had unauthorized access to AMCA's systems between Aug. 1, 2018 and March 30, 2019, and that the affected system held financial information such as credit card and bank account data, medical information and other personal information such as Social Security numbers.

For scale, Quest has said it serves approximately half of the physicians and hospitals in the United States and operates more than 2,000 locations and laboratories. The disclosure landed the same day, Oct. 22, 2026, as the company's third-quarter release, which reported revenues of $3.10 billion, up 10.0% from 2025, and reported diluted earnings per share of $2.78, up 28.7% from 2025.

Bottom Line

What is established, per News4JAX, is that Quest reported unauthorized access to Quanum Lab Services Manager in a Thursday regulatory filing, believes certain patient records were accessed, discovered the issue Wednesday, notified federal law enforcement and engaged outside cybersecurity experts. Quest also confirmed to The Associated Press that, based on its investigation to date, the incident was not related to the newly disclosed PHP vulnerabilities. Interpretation: because neither the patient count nor the data categories involved have been disclosed, the practical significance of this incident cannot yet be compared with Quest's prior 2016 and 2019 disclosures, and any assessment should wait for the company's completed investigation.