5 CFR §1400.203

1. (a)The incumbent of a national security position requiring eligibility for access to classified information is subject to the reinvestigation requirements of E.O. 12968.
2. (b)The incumbent of a national security position that does not require eligibility for access to classified information is subject to periodic reinvestigation at least once every five years. Such reinvestigation must be conducted using a national security questionnaire, and at a frequency and scope that will satisfy the reinvestigation requirements for both national security and public trust positions.