The Department of the Treasury (Treasury) is issuing an interim final rule to implement the provisions of section 121 of the Gramm-Leach-Bliley Act (GLBA) that authorize the Secretary of the Treasury (Secretary), in consultation with the Board of Governors of the Federal Reserve System (Board), to determine whether activities are financial in nature or incidental to a financial activity, and therefore permissible for a financial subsidiary of a national bank. The interim final rule sets forth the procedure whereby a national bank or other interested party may request the Secretary to make such a determination.