A significant data breach at Paradigm Healthcare Services has exposed sensitive information of over 970,000 Medi-Cal members, as reported to the US Department of Health and Human Services (HHS). The breach, which occurred last year, marks a substantial cybersecurity incident affecting California’s Medicaid program.
Details of the Paradigm Healthcare Breach
Paradigm Healthcare, located in San Francisco, is responsible for processing billing for Medi-Cal under an agreement with the California Department of Health Care Services (DHCS). The company holds Medi-Cal member identification numbers on behalf of the department. Unauthorized access to Paradigm’s local network was detected on October 13, 2025, and it was later determined that files containing personal health information were accessed between October 8 and October 15, 2025.
The breached data includes names, dates of birth, gender, and Medi-Cal member identification numbers. Paradigm clarified that their Student Health Network (SHN) platform remained unaffected. Despite the breach, the company emphasized that there is no evidence of data misuse for fraud or identity theft.
Response and Investigation
Paradigm’s notification to affected individuals was sent nearly a year after the breach was initially detected, dated September 14, 2026. The notification lacked details on the perpetrator, the method of access, or any data exfiltration. Paradigm took immediate actions, such as taking specific systems offline, notifying law enforcement, and engaging external incident response experts to address the breach.
No cybercrime group has claimed responsibility for this breach, and investigations are ongoing. The precise impact and method of compromise remain undisclosed, reflecting the complexity and scale of modern cybersecurity threats.
Other Notable Healthcare Data Breaches
In addition to Paradigm, other healthcare entities have reported significant data breaches. The law firm Tarter Krinsky & Drogin (TKD) and Ridgeway Pharmacy Ltd have also disclosed breaches affecting numerous individuals. TKD informed HHS of a breach impacting over 196,000 people, discovered from suspicious network activity in September 2025.
Ridgeway Pharmacy reported unauthorized access to its systems in August 2026, affecting over 258,000 individuals. The breach compromised data such as names, addresses, birth dates, health, insurance, and payment card information.
These incidents highlight ongoing vulnerabilities in healthcare data security, underscoring the need for robust cyber defenses to protect sensitive personal information.
