Quest Discloses Breach of Lab Ordering System to SEC

Patients of doctors' offices and hospitals that use Quest Diagnostics may need to watch for notices after hackers accessed records in Quanum, the lab ordering and billing system Quest told regulators was hit by unauthorized access. The company learned of the attack on Wednesday and filed an 8-K disclosure with the Securities and Exchange Commission.

Quanum carries patient health records along with diagnostic and billing data. Quest said the unauthorized access reached certain patient records. Its own security notice says protected health information was taken, including personal information and patient records, though the company has not identified which data types were taken or how many records were affected.

Quest has not said when the breach began, how many healthcare customers or patients are involved, or whether an attacker made a ransom demand. The company said it notified law enforcement and is investigating. Amanda Rivera, a Quest spokesperson, declined to answer questions beyond the security notice. The notice page carries noindex code, which keeps search engines from listing it.

Quest's website says about 500,000 clinicians use Quanum across thousands of North American locations. A 2026 case study on the site describes one health system with more than 6 million patients and hundreds of millions of related documents and charts. Quest has not said how many records Quanum holds.

Healthcare has drawn repeated attacks this year. In March, an incident wiped employee devices at Stryker. In August, a hack forced Boston Scientific's network offline for weeks, which the company called global disruption to operations. Breaches at CareCloud, Craneware and McKesson also exposed patient data. In 2019, Quest lost 11.9 million patient records through a third-party billing company.

Quest has not scheduled a date for further disclosure beyond the filing it made Wednesday.