What to expect when being investigated for a SAP.
If you are being investigated for a Top Secret clearance or for a Secret clearance that requires access to a designated Secret Special Access Program (SAP), an Enhanced Subject Interview (ESI) is a regular part of the investigation.
ESIs can also be required in an investigation for a Confidential or Secret clearance, if a suitability/security issue is listed on your clearance application or surfaces during the investigation. A Special Interview (SPIN) can be required in any investigation, if a previously undisclosed suitability/security issue surfaces after an ESI was conducted.