The OIG is an executive branch agency of the District of Columbia government that conducts audits, inspections, and investigations of government programs and operations. The OIG promotes economy, efficiency, and effectiveness, and detects and deters fraud, waste and mismanagement throughout the government.

In carrying out its duties and responsibilities, the OIG refers all evidence of criminal violations that it uncovers to the US Department of Justice. To ensure the OIG's independence, statutory requirements mandate that the Inspector General be appointed for a six-year term, without regard to party affiliation, solely on the basis of integrity and demonstrated ability in accounting, auditing, financial management analysis, public administration, or investigations.