The Public Company Accounting Oversight Board (PCAOB) is a nonprofit entity that was created with the passage of the Sarbanes-Oxley Act of 2002 and established by Congress to oversee the audits of public companies with the goal of protecting investors and the public's interest by promoting accurate and independent audit reports (About the PCAOB). In addition to its oversight of public company audits, the PCAOB also oversees the audits of brokers and dealers (About the PCAOB). Much like the Securities and Exchange Commission (SEC), the PCAOB's mission is to protect investors.

 The PCAOB is comprised of a five-member board (the "Board") appointed by the SEC (with input from the Secretary of the Treasury and Chair of the Board of Governors of the Federal Reserve System) and each Board member is appointed to a staggered five-year term (About the PCAOB). In addition to appointing the Board members, the SEC provides oversight of the PCAOB through the approval of its rules, standards, and budget (About the PCAOB).

Two advisory groups act as a support and advice mechanism to the Board, the Investor Advisory Group and the Standing Advisory Group. The Investor Advisory Group provides the Board members with their views and advice regarding PCAOB matters that affect investors (Investor Advisory Group). The Standing Advisory Group provides the Board members with advice regarding the development of audit and audit-related standards (Standing Advisory Group).

The PCAOB has a number of on-going obligations. One of its primary responsibilities is to establish auditing and professional standards, which the public accounting firms registered with the PCAOB must follow in their role of preparing and issuing audit reports of public companies or broker-dealers (Standards). The PCAOB also undertakes periodic inspections of registered accounting firms to determine whether a firm is in compliance with the Sarbanes-Oxley Act, the PCAOB's rules, the SEC's rules, and relevant professional standards (Inspections). In conjunction with its authority to inspect, the PCAOB can also investigate and discipline registered accounting firms and their employees who have been found to be in non-compliance with rules and standards. (Enforcement). 

As a result of its role and responsibilities, the PCAOB has broad authority in regard to accounting firms that audit public companies and broker-dealers. Through its oversight of registered accounting firms, the PCAOB plays an important role in investor protection.