In the Army, not every MOS (Military Occupational Specialty) or Soldier needs a Secret or Top Secret clearance. However, having a Secret clearance can open many doors for Soldiers looking to reclassify to another MOS or find a civilian job.
All Officer Candidate School (AR 350-1) applicants must, “e. have a SECRET security clearance.” My MOS (21C Bridge Crewmember) is closely related to a combat arms MOS (21B Combat Engineer) and it seems that everyone who handles explosives and gets demolition training is investigated during the enlistment and trainee period. Mail clerks – I think – get vetted as a rule for a Secret clearance.
You may have a Secret clearance and not know it. Look in Section II – Security Data of your Enlisted Record Brief (ERB). You should see your Personnel Security Investigation or PSI Status as "SECRET." Also look for “PSI Invest” and “PSI Invest Compl, “for dates to see if a PSI has been started and if it was completed. Mine took approximately six months to complete.
The simple answer is for you to ask your first line supervisor about getting a Secret clearance. You may not be eligible to be a candidate for a security clearance based on your job. Your NCO Support Channel can answer that question. They in turn can get more details from the S-2 shop. If everyone in your platoon has a secret clearance, perhaps you should too.
The process involves a long questionnaire (Standard Form 86) and possibly a personal interview. Be aware, financial issues and convictions (DWI) can prevent you from getting a clearance