On April 13, 2023, John Muir Health (“JMH”) filed a notice of data breach with the California Attorney general after learning that an error resulted in confidential patient information being exposed to unauthorized parties. Based on the company’s official filing, the incident resulted in an unauthorized party gaining access to consumers’ protected health information. After confirming that consumer data was leaked, JMH began sending out data breach notification letters to all individuals who were impacted by the recent data security incident.

If you received a data breach notification from John Muir Health or Walnut Creek Medical Center, it is essential you understand what is at risk and what you can do about it. To learn more about how to protect yourself from becoming a victim of fraud or identity theft and what your legal options are in the wake of the John Muir Health Walnut Creek Medical Center data breach, please see our recent piece on the topic here.

What We Know So Far About the John Muir Health Walnut Creek Medical Center Breach

News of the John Muir Health Walnut Creek Medical Center data breach is still fresh; however, what we know at this point comes from the company’s filing with the Attorney General of California. According to this source, on July 1, 2021, an employee of JMH Walnut Creek Medical Center created a website that linked to an Excel file containing patient information. This website was to facilitate more efficient communication among staff members about the use of certain medical devices. On March 22, 2023, JMH learned of the website and that it contained links to confidential patient information. On March 24, 2023, the website was disabled.

In response to learning about the incident, JMH launched an investigation. The investigation confirmed that no one without authorization accessed the patient data between September 28, 2022 and March 23, 2023. However, JWH was unable to rule out unauthorized access between July 1, 2021 and September 27, 2022.

Upon discovering that sensitive consumer data was made available to an unauthorized party, John Muir Health Walnut Creek Medical Center began to review the affected files to determine what information was compromised and which consumers were impacted. While the breached information varies depending on the individual, it may include your protected health information.

On April 13, 2023, John Muir Health Walnut Creek Medical Center sent out data breach letters to all individuals whose information was compromised as a result of the recent data security incident.

More Information About John Muir Health

Founded in 1997, John Muir Health is a healthcare organization based in Walnut Creek, California. John Muir Health includes two of the largest medical centers in Contra Costa County: Walnut Creek Medical Center and Concord Medical Center. John Muir Health also offers inpatient and outpatient behavioral health services at its Behavioral Health Center, a 73-bed psychiatric hospital in Concord, CA. John Muir Health Walnut Creek Medical Center employs more than 6,000 people and generates approximately $1.3 billion in annual revenue.