Did Kaiser Foundation Health Plan have a data breach?

Answer

Yes. Kaiser Foundation Health Plan reported a data breach to the CA Attorney General on March 12, 2026. The filing lists about 13,400,000 people affected.

What the filing says

Reported to: California Attorney General
Filing date: March 12, 2026
Breach date: April 12, 2024
People affected: 13,400,000
Type of incident: Unauthorized Disclosure

Information involved

member names
IP addresses
health-related web activity

In plain terms

Kaiser Foundation Health Plan in California reported an unauthorized disclosure affecting 13.4 million individuals. Online tracking technologies transmitted member names, IP addresses, and health-related web activity to third-party vendors.

Kaiser Foundation Health Plan has filed a data breach report with the California Attorney General, indicating an unauthorized disclosure affecting approximately 13,400,000 individuals. The incident occurred on April 12, 2024, and was officially reported on March 12, 2026.

According to the official filing, the breach stemmed from the use of online tracking technologies. These tools inadvertently transmitted certain member information to third-party vendors without proper authorization.

The specific categories of data identified as exposed include member names, IP addresses, and health-related web activity. These details are based directly on the information provided in the public breach filing.

Individuals potentially affected by this disclosure should remain vigilant about their online privacy. It is advisable to review privacy settings on all accounts and be cautious of unsolicited communications, as a general protective measure.

The investigation into this incident is currently ongoing, with authorities continuing to monitor the situation. This information reflects details available from the official regulatory filing.

Commonly recommended next steps

Check for medical identity theft
Review the Explanation of Benefits statements from your health insurer for services or claims you never received, which can signal misuse of your medical identity.
Stay alert to targeted scams
Be cautious of calls, texts, or emails that reference this breach. Legitimate organizations won't ask you to confirm sensitive details through an unsolicited message.
Keep your notification letter
Save the notice you received. It documents that your information was involved and is often needed to enroll in any credit monitoring offered or to join a related legal claim.

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DataBreachSearch.com reports what was filed with state regulators. It is not legal advice, is not a law firm, and is not affiliated with any government agency or with Kaiser Foundation Health Plan.