The Office of Investigation (OI) conducts criminal and administrative investigations to prevent fraud, waste, and abuse in HUD programs. OI has 7 regional offices and 39 field offices. OI’s highly skilled team consists of criminal investigators who exercise statutory law enforcement authority to make arrests, execute search warrants, and serve subpoenas. This team also collaborates with forensic auditors, information technology specialists, investigative analysts, and administrative support staff.

In general, OI focuses its investigations on possible violations of federal, state, and local laws or regulations in the administration of HUD programs and activities or misconduct on the part of HUD employees or the recipients of HUD funds. OIG is obligated to detect and deter fraud and criminal activities throughout all of HUD's programs and those entities HUD oversees.

Investigations may result in criminal charges, civil complaints, and administrative sanctions and decisions. Criminal charges filed against individuals or entities may result in criminal prosecutions, plea agreements, incarceration, restitution, fines, and penalties. Civil claims can lead to settlements or verdicts with restitution, fines, penalties, forfeitures, assessments, exclusion of individuals or entities from participation in Federal programs, administrative sanctions, and personnel actions.