TriZetto breach exposes health and personal data of 3.4 million people

Health technology giant TriZetto has confirmed that the personal and health-related information of more than 3.4 million people was stolen in a 2024 cyberattack, an intrusion the company did not detect for nearly a full year.

TriZetto, owned by multinational conglomerate Cognizant, serves approximately 200 million people through 875,000 healthcare providers across the United States, according to its website. Doctors' offices and healthcare providers use the company's systems to verify patients' insurance coverage for medical treatment.

In a filing submitted Friday to the Maine attorney general, TriZetto said hackers stole patients' insurance eligibility transaction reports from its servers.

The compromised data includes personal details such as patients' names, dates of birth, home addresses, and Social Security numbers. It also includes healthcare-related information, including the provider's name, demographics, and health and insurance details.

TriZetto said it discovered the breach on October 2, 2025, but later found that the hackers had gained access as early as November 2024.

Cognizant spokesperson William Abelson said the company "eliminated the threat" from its environment, but did not explain why the breach went undetected for about a year.

Several organisations have since confirmed that their patients' data was exposed in the cyberattack. Among them is OCHIN, a nonprofit consulting organisation that provides healthcare technology to roughly 300 rural and community healthcare providers across the United States. Other healthcare providers in California have also confirmed that their patients were affected.

According to TriZetto, the breach did not impact every customer.

TriZetto is the latest major health technology company to disclose a significant cyberattack in recent years.

In 2024, another major health tech company, Change Healthcare, was hit by a ransomware attack that allowed hackers to steal more than 192 million patient files. Change Healthcare processes around 15 billion healthcare transactions, and the attack triggered outages across the United States, leaving many people without access to medications or medical treatment.