T his report provides an overview of statutory inspectors general (IGs) in the federal government, including their structure, functions, and related issues for Congress. Statutory inspectors general (IGs) are intended to be independent, nonpartisan officials who prevent and detect waste, fraud, abuse, and mismanagement within federal departments and agencies. To execute their missions, IGs lead offices of inspector general (OIGs) that conduct audits, investigations, and other evaluations of agency programs and operations and produce recommendations to improve them. Statutory IGs exist in more than 70 federal entities, including departments, agencies, boards, commissions, and government-sponsored enterprises. The origins of the modern-day IGs can be traced back to the late 1950s, with the statutory establishment of an "IG and Comptroller" for the Department of State in 1959 and administrative creation of an IG for the Department of Agriculture. Prior to the establishment of IGs in the federal government, agencies often employed internal audit and investigative units to combat waste, fraud, and abuse. Congress established the first statutory IG that resembles the modern-day model in 1976 for the Department of Health, Education, and Welfare (HEW; now the Department of Health and Human Services). Congressional investigations uncovered widespread inefficiencies and mismanagement of the department's programs and operations, as well as weaknesses within the department's audit and investigative units. The House Committee on Government Operations investigative report recommended, among other things, that the Secretary of HEW place all audit and investigation units "under the direction of a single official who reports directly to the Secretary and has no program operating responsibilities" who would be responsible for identifying "serious problems" and "lack of progress in correcting such problems." Congress ultimately established the HEW IG under this model. Congress also established the Department of Energy IG under a similar model in 1977. The establishment of the HEW and Department of Energy IGs laid the groundwork for Congress to create additional statutory IGs through the Inspector General Act of 1978 (hereinafter IG Act). According to the Senate Committee on Governmental Affairs report that accompanied the bill that became law, the committee believed that extending the IG concept to more agencies would ultimately improve government programs and operations. The committee further identified IG independence from agency management as a key characteristic in fostering such improvements. The IG Act initially created 12 IGs for federal "establishments" and provided a blueprint for IG authorities and responsibilities. The act laid out three primary purposes for IGs: 1. conduct audits and investigations of programs and operations of their affiliated federal entities; 2. recommend policies that promote the efficiency, economy, and effectiveness of agency programs and operations, as well as preventing and detecting waste, fraud, and abuse; and 3. keep the affiliated entity head and Congress "fully and currently informed" of fraud and "other serious problems, abuses, and deficiencies" in such programs and operations, as well as progress in implementing related corrective actions. Congress has substantially amended the IG Act three times since its enactment, as described below. The amendments generally aimed to expand the number of statutory IGs and enhance their independence, transparency, and accountability. The Inspector General Act Amendments of 1988 (P.L. 100-504) expanded the total number of statutory IGs, particularly by authorizing additional establishment IGs and creating a new category of IGs for "designated federal entities" (DFEs). The act also established a uniform salary rate and separate appropriations accounts for each establishment IG. Further, the act added several new semiannual reporting requirements for IGs, such as a requirement for IGs to provide a list of each audit report issued during the reporting period. Finally, the law required external peer reviews of OIGs, during which a federal "audit entity" reviews each OIG's internal controls and compliance with audit standards. The Inspector General Reform Act of 2008 (P.L. 110-409) established a new Council of Inspectors General on Integrity and Efficiency (CIGIE) to coordinate and oversee the IG community, including an Integrity Committee to investigate alleged IG wrongdoing. The law also increased the uniform salary rate for establishment IGs and established a salary formula for DFE IGs. The act also provided additional authorities and protections to enhance the independence of IGs, such as budget protections, access to independent legal counsel, and advanced congressional notification for the removal or transfer of IGs. Finally, the act further amended IG semiannual reporting obligations and required OIG websites to include all completed audits and reports. The Inspector General Empowerment Act of 2016 (P.L. 114-317) aimed to enhance IG access to and use of agency records. The act exempted IGs from the Computer Matching and Privacy Protection Act (CMPPA), which is intended to allow IGs to conduct computerized data comparisons across different agency automated record systems without restrictions in the law. The act also directed CIGIE to resolve jurisdictional disputes between IGs and altered the membership structure and investigatory procedures of the CIGIE Integrity Committee. Regarding transparency and accountability, the act required IGs to submit any documents containing recommendations for corrective action to agency heads and congressional committees of jurisdiction, as well as any Member of Congress or other individuals upon request. Statutory IGs may be grouped into four types: (1) establishment, (2) DFE, (3) other permanent, and (4) special. Federal laws explicitly define the first two types of IGs but not the latter two types, though stakeholders sometimes describe IGs in this way. Consequently, this report groups IGs into the four types based on criteria that are commonly used to distinguish between IGs, including authorizing statute, appointment method, affiliated federal entity and the branch of government in which it is located, oversight jurisdiction, and oversight duration. Table 1 describes each IG type according to these criteria. As of January 2019, 74 statutory IGs operated in the federal government. The IG Act governs 65 IGs, including 33 establishment and 32 DFE IGs. The remaining nine IGs are governed by individual statutes outside the IG Act, including seven other permanent and two special IGs ( Figure 1 ). Five out of seven other permanent IGs operate for legislative branch agencies—the Architect of the Capitol (AOC), Government Publishing Office (GPO), Government Accountability Office (GAO), Library of Congress (LOC), and U.S. Capitol Police (USCP). The remaining two operate for executive branch intelligence agencies—the Central Intelligence Agency (CIA) and Intelligence Community (IC). The two special IGs include those for Afghanistan Reconstruction (SIGAR) and the Troubled Asset Relief Program (SIGTARP). Appendix A lists current statutory IGs by type. The majority of IGs oversee the activities of a single affiliated federal entity and its components. For example, the IG for the Department of Homeland Security (DHS) is responsible for evaluating programs and operations of the entire department and its components, such as the Federal Emergency Management Agency. In some cases, however, multiple IGs operate for a single entity. In other cases, one IG operates for multiple entities. Two cabinet-level departments are affiliated with more than one IG: the Department of Defense (DOD) and the Department of the Treasury. Both departments have a department-wide IG and one or more separate IGs for certain components ( Table 2 ). Congress has authorized some IGs to oversee the programs, operations, and activities of more than one entity either on a permanent or temporary basis. The expansion of an IG's jurisdiction to include multiple entities has generally stemmed from agency reorganizations or congressional concern regarding oversight of a particular agency or program. Table 3 provides examples of IGs who have permanent expanded jurisdiction. In the past, Congress has also temporarily expanded IG jurisdiction to include operations of unaffiliated agencies. For example, Congress directed the GAO IG to serve concurrently as the IG for the Commission on Civil Rights for FY2012 and FY2013. The Consolidated Appropriations Act, 2014, authorized the DOT IG to oversee the Metropolitan Washington Airports Authority (MWAA), a nonfederal entity. IGs conduct reviews of government programs and operations. The genesis and frequency of such reviews can vary. An IG generally conducts a review in response to a statutory mandate, at the request of Congress or other stakeholders (e.g., the President), or upon self-initiation. Reviews can occur once or periodically. IG reviews can be grouped into three broad categories: (1) performance audits, (2) inspections or evaluations, and (3) investigations. Table 4 and the sections below discuss certain differences between the review types in terms of three characteristics: quality standards, scope of analysis, and type of analysis. IG reviews are governed by different quality standards. IG audits are subject to the generally accepted government auditing standards (GAGAS) developed by GAO. Inspections or evaluations and investigations, by contrast, are governed by separate standards developed by the CIGIE. While several standards are identical or similar across the three review types, the requirements to meet those standards differ by type. For example, one GAO report noted that IG audits are "subject to more depth in the requirements for levels of evidence and documentation supporting findings" than IG inspections. IG audits and inspections or evaluations include programmatic analysis, which may involve analyses related to the compliance, internal control, or efficiency and effectiveness of agency programs and operations. They also often include recommendations to improve such programs and operations. IG investigations, by contrast, typically include nonprogrammatic analysis and instead focus primarily on alleged misuse or mismanagement of an agency's programs, operations, or resources by an individual government employee, contractor, or grantee.