Quest Diagnostics says nearly 12 million patients may have been affected by data breach

Quest Diagnostics said Monday nearly 12 million patients’ personal information, including Social Security numbers and credit card information, may have been compromised after one of its billing collections providers reported a data breach.

American Medical Collection Agency (AMCA), a billing collections firm, first notified Quest Diagnostics and Optum360 — a Quest contractor that uses AMCA's billing services — of a possible data breach on May 14. The service provider then told the companies more than two weeks later that about 11.9 million patients were potentially affected.

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“AMCA believes this information includes personal information, including certain financial data, Social Security numbers, and medical information, but not laboratory test results,” Quest Diagnostics said in a statement.

Quest Diagnostics said it was looking into the issue and hasn’t been able to verify AMCA’s information. The company added it was still waiting for a complete report of the data security incident that identified which patients were affected, but has since suspended work with AMCA.


"Quest will be working with Optum360 to ensure that Quest patients are appropriately notified consistent with the law," the company added. "We are committed to keeping our patients, health care providers, and all relevant parties informed as we learn more."