Summary: Pursuant to a congressional request, GAO evaluated the Agency for International Development's (AID) Office of Inspector General's (OIG) management and operation, focusing on: (1) OIG policies and procedures for planning and conducting its work; (2) OIG audit work in high-risk areas; (3) OIG audit reports and closed investigations; and (4) the American Foreign Service Association's concerns over OIG management and working relationships. GAO noted that: (1) OIG is sufficiently independent to fulfill its responsibilities without interference from AID management; (2) OIG has addressed several identified high-risk areas, presented information fairly, and suggested numerous constructive recommendations for improving AID operations; (3) OIG has conducted reasonable and thorough investigations, although some case files are missing investigative plans and reports; (4) OIG has issued guidance to better explain the purpose and use of management representation letters; and (5) because AID and AID OIG have recently undergone significant managerial and operational changes and expect further restructuring, GAO did not investigate the effectiveness of working relationships between OIG and AID management.