DETROIT (Michigan News Source) – Welltok Inc. says more than one million Southeastern Michiganders are affected by a cybersecurity breach at the company.

The company provides a healthy lifestyle portal for Priority Health and communications services for Corewell Health’s southeastern Michigan properties. The company says roughly 2,500 Priority Health members had their names, addresses and health insurance numbers compromised while more than one million Corewell Health patients had their name, birth date, email addresses, phone number, medical diagnoses, health insurance information or Social Security number compromised.

MORE NEWS: Michigan’s Caregivers Face a Familiar Union Dues Strategy

Letters have been sent to individuals who are impacted by the breach.

The cyberattack at Welltok is the fourth-largest healthcare data breach in the U.S. this year. The U.S. Department of Health and Human Services says that data breaches among health care organizations more than doubled from 2019 to 2021. In 2022, at least 28 million health care records were breached.