<P> In the United States , a security clearance is an official determination that an individual may access information classified by the United States Government . Security clearances are hierarchical ; each level grants the holder access to information in that level and the levels below it . The clearance process requires a background investigation and the signing of a nondisclosure agreement . Access to any particular piece of information requires `` need - to - know . '' In some cases , this requirement is only nominal , as some classified information is widely published on secure networks . In other cases , there is a formal need - to - know determination . In addition to such a determination , Special Access Programs and Sensitive Compartmented Information may require additional investigation and adjudication of the prospective clearance holder . </P>
what is security clearance for jobs in usa
an official determination that an individual may access information classified by the United States Government