Munson Healthcare Under Investigation for Data Breach of Over 100,000 Patient Records

Schubert Jonckheer & Kolbe LLP is investigating a data breach that led to unauthorized access to the sensitive information of 101,891 patients of Munson Healthcare, the largest health system in Northern Michigan.

On or around January 22, 2025, an unauthorized third party gained access to personal health information on legacy Cerner electronic health record systems that Munson Healthcare utilizes. Cerner, now Oracle Health, confirmed that a hacker gained access to two of its legacy servers and potentially stole a range of personal and health information, which has affected 80 hospitals to date.

Although the breach occurred in January 2025, Munson Healthcare did not notify impacted individuals until on or around January 26, 2026, which may have violated state and federal laws. The following data may have been compromised in the breach: patient names, Social Security numbers, medical record numbers, doctors, diagnoses, medicines, test results, images, care and treatment.

If your personal information was impacted by this incident, you may be at risk of identity theft and other serious violations of your privacy. As a result, you may be entitled to money damages and an injunction requiring changes to Munson Healthcare’s cybersecurity practices.

If you received notification of this data breach or are a patient of Munson Healthcare and wish to obtain additional information about your legal rights, please fill out the form below.