The Individual Ready Reserve, or IRR, serves as a strategic reserve of trained military manpower. Military veterans typically serve six years of an eight year total enlistment either on active duty or in a troop program unit (TPU), and spend the remaining two years in the individual ready reserve prior to being discharged from military service altogether. Transfer from a troop program unit, or selected reserve status, to the IRR happens automatically for reserve component soldiers who complete the selective reserve or active duty portion of their enlistments. Officers must generally resign their posts and request transfer, unless they are passed over for promotion twice, in which case they will be involuntarily reassigned.
Complete your enlistment
Complete your enlistment. Enlisted soldiers are typically expected to complete their terms of service with the troop program unit except in cases of severe hardship. This is especially true of soldiers who have collected an enlistment bonus. Those who transfer to the IRR before the terms of their enlistments are up must generally repay a prorated portion of any enlistment bonuses received.
Resign your post
Resign your post if you're a commissioned officer. Officers are generally free to resign their posts and transfer to the IRR at any time unless there is a stop-loss order on the unit. However, they may have to pay back ROTC scholarship money or reimburse the U.S. Military Academy if they resign prior to their first eight years of service.
Write a letter
Write a letter to your commander requesting the transfer to the IRR. If you are requesting the transfer because of a hardship or because you are relocating more than 50 miles from a drilling unit, explain the reasons in your letter. Don't assume your commander knows already. If he does, he will still have to forward the request up the chain of command for approval.
Have your commander sign the Form 4187
Have your commander sign the Form 4187, authorizing your transfer to the Individual Ready Reserve. This form must be endorsed at several different levels before the transfer actually takes place. Check with your supervisor or admin NCO to monitor the progress of the request.
Continue drilling with your current unit
Continue drilling with your current unit to accrue retirement points until you receive your orders officially placing you in the IRR.