OATH was established by Executive Order No. 32 in 1979, to professionalize the administrative hearing system serving City government. OATH was made a Charter agency in 1988, as part of the Charter revisions which enacted the City Administrative Procedure Act (CAPA). Among CAPA's primary reforms was the adoption of minimum standards for the conduct of administrative hearings and the establishment of OATH as the first municipal central tribunal in the country separate from the agencies that refer cases to it.
Removing adjudications from within agencies was a primary objective of the Charter revisers. The creation of a central independent decision-maker fosters increased confidence in the fairness of the administrative hearing process. The Charter revisers further secured this objective by granting five-year terms to OATH's administrative law judges to enhance their impartiality.
Initially, OATH's caseload consisted of mostly disciplinary cases brought by City agencies against civil service employees. With the 1988 Charter revisions giving OATH general jurisdiction, the types of cases referred to OATH have substantially increased. City agencies now refer matters pertaining to licensing, regulatory, and enforcement authority, including cases involving City contractors, holders of various City licenses, and loft tenants and their landlords. In 2004, as a result of court rulings including the Second Circuit's decision in Krimstock v. Kelly, OATH acquired jurisdiction over hearings conducted after the NYPD seizes the vehicles of drivers accused of crimes. These hearings determine whether or not the City's retention of a vehicle is lawful and necessary.
On August 12, 2008, Mayor Bloomberg signed Local Law 35 that consolidated the Environmental Control Board (ECB) under OATH. ECB is the City's largest tribunal, adjudicating some 250,000 violations per year. Under OATH’s management, ECB eliminated a backlog of more than 7,000 cases, decreased the average wait time for decisions from more than 90 days to 10 days, and has increased access to justice by providing hearings and appeals online, hearings by phone, and educational materials for the public about the hearing process.
Due to the proven success of the ECB consolidation, on June 8, 2011, Mayor Bloomberg signed Executive Order 148 which further expanded OATH’s jurisdiction by transferring the management of the administrative tribunals traditionally overseen by the Department of Health and Mental Hygiene (DOHMH) and the Taxi and Limousine Commission (TLC) to OATH. OATH is currently comprised of four different tribunals; it is responsible for holding more than 300,000 hearings on a diverse range of issues, annually.