This is the 2011 revision of Government Auditing Standards, commonly referred to as the "Yellow Book." Contains the auditing standards promulgated by the Comptroller General of the United States. Includes the professional standards and guidance, commonly referred to as generally accepted government auditing standards (GAGAS), which provide a framework for conducting high quality government audits and attestation engagements with competence, integrity, objectivity, and independence. These standards are for use by auditors of government entities and entities that receive government awards and audit organizations performing GAGAS audits and attestation engagements. This revision supersedes the 2007 revision. It contains the following major changes from the 2007 revision that reinforce the principles of transparency and accountability and provide the framework for high-quality government audits that add value: 1) A conceptual framework for independence was added to provide a means for auditors to assess their independence for activities that are not expressly prohibited in the standards. This more principles-based approach to analyzing independence provides the framework for auditors to assess the unique facts and circumstances that arise during their work; 2) This revision drops discussion surrounding certain AICPA Statements on Auditing Standards (SAS) and Statements on Standards for Attestation Engagements (SSAE) requirements that were incorporated by reference and included in the 2007 revision, as the standards have converged in those areas; and, 3) The definition of validity as an aspect of the quality of evidence has been clarified for performance audits. Effective with the implementation dates for the 2011 revision of Government Auditing Standards, GAO is also retiring Government Auditing Standards: Answers to Independence Standard Questions (GAO-02-870G, July 2002). This revision of the standards has gone through an extensive deliberative process, including public comments and input from the Comptroller General's Advisory Council on Government Auditing Standards. The Advisory Council generally consists of about 25 experts in financial and performance auditing and reporting drawn from federal, state, and local government; the private sector; and academia. The views of all parties were thoroughly considered in finalizing the standards. The 2011 revision of Government Auditing Standards will be effective for financial audits and attestation engagements for periods ending on or after December 15, 2012, and for performance audits beginning on or after December 15, 2011. (GAO-12-331G). YELLOW Book.