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Defendant Name: JOHANNA A. MAYER, individually, and on behalf of all others similarly situated

Case Number: 5:19-cv-01029-JGB-SHK


Practice Area: Class Action

Status: Active; Jury Trial Demanded

Date Filed: 06/05/19

Documents: Original Complaint (PDF)

Attorneys Involved: Brian Chase, Ian M. Silvers

Think you have a case? Contact us using the form to the right to have a class action specialist contact you.

Details of the Quest Diagnostics Data Breach

On June 3, 2019, Quest Diagnostics, one of the largest blood testing providers in the country, announced a data breach whereby nearly 12 million of its customers, including Plaintiff and putative Class members, had their personally identifiably information (“PII”) and protected health information (“PHI”) accessed by unauthorized parties due to the negligent data security of AMCA, one if its billing collections vendors (the “Data Breach”). Specifically, the PII and PHI accessed included, but was not limited to, Plaintiff’s and Class members’ personal information (e.g. Social Security Numbers), financial information (credit card numbers and bank account information), and medical information.

In its SEC filing relating to the Data Breach, Quest Diagnostics announced that unauthorized parties accessed between August 1, 2018 and March 30, 2019 AMCA’s system, which contained Plaintiff’s and Class members’ PII and PHI. Despite unauthorized parties having access to the AMCA system for more than six months, AMCA only learned of the Data Breach as a result of receiving information from a security compliance firm that works with credit card companies.

Given AMCA’s relationship to Question Diagnostics (AMCA provides services to Optum360, which in turn provides payment services to Quest Diagnostics), Plaintiff and Class members were blindsided by the Data Breach announcement given most have never heard of AMCA or Optum360 and were unaware that their information would be shared with these entities, causing additional emotional harm.


Beginning around August 1, 2018, unauthorized parties accessed the AMCA system that contained Plaintiff’s and Class members’ PII and PHI. Plaintiff and Class members are customers who paid and provided their PII and PHI to Quest Diagnostics in exchange for diagnostic and medical services. Quest Diagnostics provided Plaintiff and Class members’ PII and PHI to Optum360 who in turn provided that information to AMCA for billing and collection purposes.

For more than six months, unauthorized parties maintained uninterrupted access to the AMCA system, containing the PII and PHI of nearly 12 million customers of Quest Diagnostics.

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