People search Health Net data breach timeline because regulated data and trust are existential—one incident triggers class actions and regulator exams. BreachHistory indexes 8 Health Net-linked incidents, with headline counts up to 1.9M+ in catalog rows. This page maps every attested event through 2026 with internal links to canonical records.
Why Health Net breach history matters
Health Net operates in Healthcare. Across indexed rows, recurring themes include mixed intrusion and disclosure events. Understanding the chronological pattern helps security teams, customers, and regulators separate confirmed disclosures from forum marketing.
Full timeline through 2026
2013 — — Health Net: A number of member identification cards were mailed…
Cataloged incident. A number of member identification cards were mailed to incorrect addresses. The problem occurred because of a programming error. The member identification cards contained names, dates of enrollment, addresses, telephone numbers of primary care physicians, issue dates of cards, and Medi-Cal client identification numbers. Exposed categories include Personal information. No attested victim count is published for this row yet. See the health-net2013 and canonical BreachHistory entry.
2011 — — Health Net: Nine disc drives that contained sensitive health…
Cataloged incident. Nine disc drives that contained sensitive health information went missing from Health Net's data center in Rancho Cordova, California. The drives contained the personal information of 1.9 million current and former policyholders, compromising their names, addresses, health information, Social Security numbers and financial information. The 1.9 million victims include 622,000 California residents enrolled in Health Net HMOs, 223,000 Californians enrolled in Health Net PPOs and people enrolled in Exposed categories include Personal information. BreachHistory cites approximately 1.9M+ affected records in this row. See the health-net2011 and canonical BreachHistory entry.
2011 — — Health Net: Several server drives, containing personal…
Cataloged incident. Several server drives, containing personal information of former and current employees, went missing. BreachHistory cites approximately 1.9M+ affected records in this row. See the health-net-ibmu and canonical BreachHistory entry.
2010 — — Health Net: Customer information was sent to the wrong agent, 18 records
Cataloged incident. Customer information was sent to the wrong agent. The format of the information is unknown. The information included names and Medicare numbers. Exposed categories include Personal information. BreachHistory cites approximately 18 affected records in this row. See the health-net2010 and canonical BreachHistory entry.
2009 — — Health Net: The personal information for almost half a million…
Cataloged incident. The personal information for almost half a million Connecticut residents could be at risk after a portable disk drive disappeared from Health Net in May of 2009. Health Net is a regional health plan and the drive included health information, Social Security number and bank account numbers for all 446,000 Connecticut patients, 1.5 million nationally. The information had been compressed, but not encrypted, although a specialized computer program is required to read it. Patients in Arizona, New Jer Exposed categories include Personal information. BreachHistory cites approximately 1.5M+ affected records in this row. See the health-net2009 and canonical BreachHistory entry.
2009 — — Health Net: A portable hard drive with seven years of personal…
Cataloged incident. A portable hard drive with seven years of personal and medical information on about 1.5 million Health Net customers was lost for six months before being reported. BreachHistory cites approximately 1.5M+ affected records in this row. See the health-netu and canonical BreachHistory entry.
2009 — — Health Net: Lost / stolen device, 500,000 records
Cataloged incident. Data breach reported. healthcare organization. Method: lost / stolen media. Source: Wikipedia List of data breaches. Exposed categories include Personal and demographic data. BreachHistory cites approximately 500K+ affected records in this row. See the health-net2009-500000-wiki2 and canonical BreachHistory entry.
2008 — — Health Net: Thousands of Health Net employees in Connecticut…
Cataloged incident. Thousands of Health Net employees in Connecticut and other states have been notified that their names and Social Security numbers were on a laptop computer that was stolen more than a month ago from a company vendor. The laptop had information on about 5,000 employees companywide and an undisclosed number of health-care providers outside the Northeast. Exposed categories include Personal information. BreachHistory cites approximately 5K+ affected records in this row. See the health-net2008 and canonical BreachHistory entry.
Patterns and analysis
- Mixed intrusion and disclosure events — appears across multiple Health Net catalog entries; prioritize controls that address this class of failure.
- Record-count hygiene — BreachHistory indexes actor-cited figures separately from company-confirmed totals; read each row's technicalWriteup before treating counts as fact.
- 2026 monitoring — New disclosures roll into this timeline as they are verified or labeled unverified per catalog policy.
What to do if you may be affected
- Step 1: Enable phishing-resistant MFA on every account tied to this brand.
- Step 2: Use unique passwords and a password manager—breach rows often involve credential reuse.
- Step 3: Monitor official company breach notices and regulator filings, not dark-web downloads.
- Step 4: Watch for medical-ID theft and billing fraud after health-data incidents.
- Step 5: Bookmark the Health Net company page for new 2026+ disclosures.
Canonical BreachHistory hub
Explore every indexed row: breachhistory.com/health-net · Latest: health-net2013.
Sources: BreachHistory catalog (8 rows for Health Net), company and regulator disclosures cited in individual breach records.