38 CFR §21.8340

1. (a)Purpose of leave of absence. The purpose of the leave system is to enable the child to maintain his or her status as an active program participant.
2. (b)Basis for leave of absence. The VR&E case manager may grant the child leaves of absence for periods during which the child fails to pursue a vocational training program. For prolonged periods of absence, the VR&E case manager may approve leaves of absence only if the case manager determines the child is unable to pursue a vocational training program through no fault of the child.
3. (c)Effect on entitlement. During a leave of absence, VA suspends the running of the basic 24-month period of entitlement, plus any extensions thereto, until the child resumes the program.