SAN FRANCISCO, Jan. 29, 2026 /PRNewswire/ -- 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.