California Physicians’ Service dba Blue Shield of California, the covered entity (CE), reported that its business associate (BA) experienced a cyber-attack that compromised the protected health information (PHI) of 636,849 individuals. The PHI involved included names, Social Security numbers, diagnoses, addresses, birthdates, and claims information. In its mitigation efforts, the CE provided complimentary credit monitoring services and implemented additional administrative, technical, and security safeguards.