- In the U.S. Army, RE Code 3 refers to those no longer qualified to enlist but who may do so if they are able to provide an appropriate waiver. Its subsections A, B, and C refer specifically to individuals who have not met certain length of service, pay-grade or aptitude requirements.
- The Navy's RE Code 3 covers more circumstances than the Army. Its subsections, A-K, represent discharges ranging from failure to meet education requirements to discharge due to pregnancy and parenthood. As with the Army, those individuals classified with the Navy, Marines and Coast Guard must present a waiver in order to become eligible for re-enlistment. Those classified as ineligible for failing to meet educational requirements must present proof that they have completed the necessary level of education in order to obtain a waiver.
- The Air Force's RE Code 3 contains subsections A-V, and generally pertains to individuals discharged prior to completing a length of service requirement or without obtaining a particular skill qualification. Subsections U and V pertain specifically to individuals discharged with Special or Voluntary Separation benefits. Again, these individuals generally must obtain waivers in order to be eligible for re-enlistment.
- Waivers are acquired from the recruiting officer with whom an individual meets during the re-enlistment process. Obtaining a waiver can be a highly subjective process depending on the officer processing the re-enlistment, the armed services' needs, and, of course, the applicant's RE Code. It is also possible for an individual to petition his or her congressman for help in obtaining a waiver.
- Military Re-entry Code 3 is a classification that represents a difficult but ultimately surmountable obstacle to re-enlistment in the United States military, depending on the circumstances of an individual's discharge and the military's ever-changing manpower demands.
