Mid Michigan Medical Billing Service, Inc. has confirmed a cyberattack that exposed sensitive health and personal information of over 28,000 individuals. The breach involved unauthorized access to files containing medical and financial data.
Mid Michigan Medical Billing Service’s Data Breach Investigation
Mid Michigan Medical Billing Service, Inc. (“MMMBS”), a revenue cycle management firm supporting healthcare providers, has disclosed a serious data breach involving 28,185 individuals. The incident began on March 27, 2025, when suspicious activity was detected on its IT network. An internal investigation later confirmed that an unauthorized actor accessed the system and copied files containing confidential data.
MMMBS responded by taking systems offline and initiating a forensic investigation. A detailed review of the impacted files revealed a wide range of sensitive information, including patient and billing data received from MMMBS’s healthcare partners. The company collaborated with those healthcare providers to notify affected individuals. The notification process concluded around December 2, 2025—over eight months after the breach occurred.
This delay in notification, though likely due to coordination requirements with partner organizations, left many individuals unaware of the potential compromise to their most sensitive personal and medical information. While MMMBS stated there is no evidence of misuse, the nature of the data involved—including health insurance details, biometric data, and Social Security numbers—poses significant identity theft risks.
MMMBS says it has enhanced its security practices and reported the incident to law enforcement and regulators. However, for individuals whose data was involved, this breach may have long-term consequences, especially if their information ends up on the dark web or is used for fraudulent purposes.
When Did This Breach Occur?
The breach occurred on March 27, 2025, and impacted individuals were notified on or around December 2, 2025.
What Information Was Breached?
Depending on the individual, the exposed information may include:
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Full name
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Date of birth
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Driver’s license or government-issued ID number
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Medicare or Medicaid identification number
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Diagnosis and treatment details
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Medical record or patient account number
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Health insurance information
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Payment card number
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Employer identification number
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Passport number
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Treating/referring provider name
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Biometric data
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Social Security number (in limited cases)
What You Can Do
If you received a notice about the Mid Michigan Medical Billing Service data breach or suspect you may be affected, take the following steps:
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Review your explanation of benefits (EOB) and medical statements for unauthorized services.
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Monitor your credit reports and bank statements for unfamiliar activity.
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Request free credit reports at annualcreditreport.com or by calling 1-877-322-8228.
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Place a fraud alert or credit freeze with the major credit bureaus.
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Watch out for phishing emails that may use stolen information to trick you.
You may also be entitled to compensation. Class Action U helps consumers explore their legal options after breaches like this. Many people don’t realize they qualify to join a lawsuit that can help recover money for lost time, expenses, and privacy violations.
File a Data Breach Lawsuit Against Mid Michigan Medical Billing Service
If Mid Michigan Medical Billing Service has notified you that your personal or medical data was compromised, you may be eligible to file a class action lawsuit. Companies that manage healthcare billing and store confidential health data must uphold the highest standards of cybersecurity. When they fail to do so, victims have the right to pursue justice.
Compensation may be available for out-of-pocket costs, time spent monitoring your credit, emotional distress, and the long-term risk of identity fraud. Don’t assume you have to face this situation alone.
Contact us at Class Action U, where we’ll connect you with a lawyer skilled in class action lawsuits. If you’ve been contacted about this breach, received notice, or discovered you were impacted, fill out our quick, easy, and secure form to sign up. There is no cost to reach out to our legal partner and no obligation after speaking with someone from our team.
