Marquette County Medical Care Data Breach Investigation

The data breach lawyers at The Lyon Firm are investigating a recent data security incident at Marquette County Medical Care Facility (MCMCF) that may have leaked a large amount of personal information. Patients and staff who think they may be impacted by the data breach should begin to take measures to mitigate the increased privacy risks and contact an experienced attorney.

Our legal team can help guide you through the class action process and we offer free case reviews. Call now for a consultation and to consider filing a complaint. MCMCF should be sending data breach notification letters out to all impacted individuals soon. 

What Happened at Marquette County Medical Care Facility?

On March 3, 2025, Marquette County Medical, a long-term and short-term care provider operating in Ishpeming, Michigan, discovered they had been the victim of a data privacy intrusion involving unauthorized access to sensitive personal and health information. The data breach allegedly originated from a business email phishing attack in which unauthorized individuals gained access to the Human Resources director’s Microsoft Office 365 account and sent emails to contacts from that company account.

A subsequent investigation concluded that the compromised information included personally identifiable information (PII) and personal health information (PHI). Compromised information may include a combination of the following: names, Social Security numbers, dates of birth, protected health information (PHI), and financial information.