This interim final rule prescribes procedures for investigations of individuals seeking to hold national security positions or perform national security duties who are required to complete Standard Form (SF) 86, "Questionnaire for National Security Positions," for the personnel security investigations (PSIs). This rule does not provide investigative instructions for individuals in nonsensitive or public trust positions. An interim final rule is required to update DoD's procedures pertaining to requests for background investigations in support of national security eligibility determinations. The existing regulation is now more than 26 years old, and procedures that have since evolved need to be incorporated into new manuals. Issuance of these procedures ensures that DoD components carry out their responsibilities for the DoD Personnel Security Program consistently, efficiently, and fairly. DoD Manual 5200.02 replaces select paragraphs of the DoD 5200.02-R, "Personnel Security Program," dated January 1987, that pertain to investigative requirements. This rule updates responsibilities and procedures for requests for investigations required for national security eligibility determinations and incorporates many requirements established and implemented through executive branch and DoD memoranda issued from 1987 to present. Procedures have also been updated to reflect changes in national level policy and advances in information technology used in the DoD Personnel Security Program.