The Board of Governors of the Federal Reserve System issued this supplemental guidance to enhance the 2003 interagency standards regarding the internal audit function and its outsourcing for institutions with over $10 billion in assets. The document outlines requirements for governance, operational effectiveness, and independence, while clarifying restrictions on external auditor services following changes to the FDI Act. It further details supervisory expectations for board oversight of outsourcing arrangements and examiner reliance on internal audit work.