If your bank is a Savings Bank (the official name of Savings Banks typically has the letters "F.S.B." or the words "Savings" or "Savings Bank" in their name), it is likely regulated by one of the regional offices of the Office of Thrift Supervision. Click the following link to get the contact information for this regulator of Savings Banks in Michigan

If your bank is nationally chartered (the official name of nationally charted banks typically has the letters "N.A." or the words "National Association" in their name), it is regulated by the Office of Comptroller of the Currency, which also has regional offices. Click here to view the local offices of the Comptroller of the Currency - Regulator of nationally charted institutions

If your local bank is state chartered, it reports to a state regulatory agency.