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Over a doctor’s shoulder we see a spreadsheet of medical data on a vulnerable hospital computer.

AltaMed Data Breach Investigation

Written by Joseph Lyon on . Posted in Data Breach.

The data breach lawyers at The Lyon Firm are investigating a recently reported data security incident at California’s AltaMed Health. A disclosure has been sent out to the California Attorney General’s office, and data breach notification letters are being sent to all known impacted individuals. Contact our legal team to assess your case and to learn more about how to file a class action complaint in order to seek compensation. We have filed numerous data breach lawsuits on behalf of plaintiffs in California and nationwide.

What Happened at AltaMed?

Back in August 2024, AltaMed Health Services Corporation allegedly experienced a serious data breach that compromised sensitive information belonging to patients and staff. The breach reportedly involved unauthorized access to a wide range of personally identifiable information (PII) and protected health information (PHI).

The exposed personal data may include the following: Social Security numbers, dates of birth, driver’s license or state identification numbers, passport numbers, foreign national ID numbers, personal email addresses, personal telephone numbers, medical record numbers, Medicare or Medicaid ID numbers, medical billing details, doctor or provider names, dates of service, payment information for health services, medical history, medical treatment details, mental or physical condition or diagnosis, procedure information, COVID-19 test results or vaccination status, prescription information, incidental health references, health insurance policy numbers, other health insurance information, handwritten signatures, genetic data, mother’s maiden name, and usernames and passwords.

The AltaMed data breach was officially disclosed to the California Attorney General’s office on June 13, 2025 and it is unclear why it took so long for the company to contact affected individuals, given the sensitive nature of the incident. The number of affected individuals has not been made public, but for those impacted, we suggest contacting an experienced attorney and to start taking steps to help mitigate your risk of fraud and identity theft.