National Background Investigations Bureau NBIB Nationales Büro für Hintergrunduntersuchungen National Background Investigations Bureau Oficina Nacional de Investigaciones de Antecedentes Oficina Nacional de Investigaciones de Antecedentes Bureau national des enquêtes de sécurité משרד החקירות הלאומי לרקע राष्ट्रीय पृष्ठभूमि जांच ब्यूरो 国家背景調査局 Bureau Nacional de Investigações de Antecedentes 国家背景调查局 NBIB National Background Investigations Bureau The National Background Investigations Bureau (NBIB) is a semi-autonomous U.S. Government agency housed within the United States Office of Personnel Management (OPM) that is responsible for conducting security clearance investigations into individuals who need to hold security clearances for employment purposes.