Understanding your MemberSource Credit Union data breach notification letter
If a MemberSource Credit Union 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
MemberSource Credit Union filed a data breach report with the Montana Attorney General on May 5, 2026, concerning an incident on June 3, 2025. This report indicates that personal information held by the credit union was compromised through unauthorized access. Individuals who received notification letters should review them for specific details on the exposure.
What to do after the letter
Confirm the notice is genuine
A legitimate MemberSource Credit Union notice references the specific incident reported to the Montana 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 MemberSource Credit Union incident against the filing reported to the Montana Attorney General. This registry summarizes what was filed; it does not provide legal advice.
This page summarizes a data breach reported to the Montana Attorney General for informational purposes. DataBreachCaseFile.com is a neutral reference registry and does not provide legal advice.