Health Net Data Breach History

This page tracks the Health Net data breach history and cybersecurity incidents affecting Health Net. BreachHistory currently indexes 8 publicly disclosed or catalogued incidents spanning 2008 through 2013, with approximately 7.3 million records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.

The Health Net breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed.

Largest Health Net Data Breaches

The largest indexed incidents include the 2011 — Health Net: Nine disc drives that contained sensitive health…, the 2011 — Health Net: Several server drives, containing personal…, and the 2009 — Health Net: The personal information for almost half a million…, along with additional historical incidents involving exposed passwords, public databases, and large-scale data scraping. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by Health Net or a regulator. Below is the list of large data breaches:

• 2011 2011 — Health Net: Nine disc drives that contained sensitive health… — about 1.9M records exposed · Catalogued incident
• 2011 2011 — Health Net: Several server drives, containing personal… — about 1.9M records exposed · Catalogued incident
• 2009 2009 — Health Net: The personal information for almost half a million… — about 1.5M records exposed · Catalogued incident
• 2009 2009 — Health Net: A portable hard drive with seven years of personal… — about 1.5M records exposed · Catalogued incident
• 2009 2009 — Health Net: Lost / stolen device, 500,000 records — about 500.0K records exposed · Catalogued incident
• 2008 2008 — Health Net: Thousands of Health Net employees in Connecticut… — about 5.0K records exposed · Catalogued incident
• 2010 2010 — Health Net: Customer information was sent to the wrong agent, 18 records — about 18 records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include health and medical (PHI) records, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

Health Net Data Breach 2026

At the time of this update, no Health Net data breach has been catalogued for 2026. New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.

What To Do If You Were Affected

If you believe your account may have been involved in a Health Net data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.

This Health Net breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.