LabCorp said approximately 7.7 million consumers are affected by a breach at third-party collections firm American Medical Collection Agency.
In a filing with the U.S. Securities and Exchange Commission on Tuesday, LabCorp said the breach happened between Aug. 1, 2018, and March 30, 2019.
Information that could have been exposed includes names, addresses, dates of birth and balance information.
Notices are being sent to LabCorp customers whose credit card or bank account information may have been accessed.
The disclosure comes one day after a collection firm that worked with Quest Diagnostics informed the medical testing company that the data of 11.9 million patients may have been affected in a breach.
American Medical Collection Agency (AMCA), a billing collections service provider, reported that "an unauthorized user had access to AMCA's system containing personal information AMCA received from various entities, including from Quest."
Forensic experts are said to be investigating the breach.