It also allows RC soldiers to continue developing their military skills. Applicable security clearance. Further progression depends upon acquiring the MOS of the higher grades within the present unit or transferring to another unit where promotion within the present MOS is still possible. The other non-waiverable requirement, attaining the appropriate security clearance, is key to a soldier's development. Certain key positions, mostly SFC and higher, require the soldier to have a secret clearance.
Clearances are expensive to process and can take a long time.
Soldiers considering a career in the reserve component can speed this up by making sure the interviewers receive all requested background information as early as possible.