Understanding your Mass General Brigham Incorporated data breach notification letter
If a Mass General Brigham Incorporated letter arrived in your mailbox, here is what it means, why you received it, and the free steps you can take right now.
Why you received this letter
Mass General Brigham Incorporated is a prominent integrated healthcare system that operates numerous hospitals, clinics, and research facilities. As a major provider of medical services, the organization collects and maintains highly sensitive personal information, including comprehensive health records, diagnostic data, and insurance details necessary for patient care and billing. In 2025, the company officially reported a data security incident to the New Hampshire Attorney General, confirming that unauthorized access to its systems occurred. If you received a data breach notification letter from Mass General Brigham, it indicates that your personal or protected health information may have been compromised during this event. This notification is intended to inform you of the incident and provide guidance on the steps you can take to protect your identity and medical privacy.
What to do after the letter
Confirm the notice is genuine
A legitimate Mass General Brigham Incorporated notice references the specific incident reported to the New Hampshire Attorney General and describes which categories of your information were involved. Compare the letter against the public filing before acting on any links or phone numbers it contains.
Keep the letter — it is your proof of connection
The notification letter is the document that ties your personal information to this incident. Keep the original and photograph it. If you later request a case review, this letter is the strongest evidence that you were among the affected individuals.
Protect your accounts and credit
Depending on what was exposed, consider a free credit freeze with all three bureaus, new passwords for reused credentials, and monitoring of financial statements. These steps are free and do not require you to wait for anyone's permission.
Check the record against the public filing
You can verify the Mass General Brigham Incorporated incident against the filing reported to the New Hampshire Attorney General. This registry summarizes what was filed; it does not provide legal advice.
This page summarizes a data breach reported to the New Hampshire Attorney General for informational purposes. DataBreachInformation.com is a neutral reference registry and does not provide legal advice.