38 CFR § 3.13 - Discharge to change status.
(a) A discharge to accept appointment as a commissioned or warrant officer, or to change from a Reserve or Regular commission to accept a commission in the other component, or to reenlist is a conditional discharge if it was issued during one of the following periods:
(1) World War I; prior to November 11, 1918. As to reenlistments, this subparagraph applies only to Army and National Guard. No involuntary extension or other restrictions existed on Navy enlistments.
(2) World War II, the Korean conflict or the Vietnam era; prior to the date the person was eligible for discharge under the point or length of service system, or under any other criteria in effect.
(3) Peacetime service; prior to the date the person was eligible for an unconditional discharge.
(b) Except as provided in paragraph (c) of this section, the entire period of service under the circumstances stated in paragraph (a) of this section constitutes one period of service and entitlement will be determined by the character of the final termination of such period of active service except that, for death pension purposes, § 3.3(b)(3) and (4) is controlling as to basic entitlement when the conditions prescribed therein are met.
(c) Despite the fact that no unconditional discharge may have been issued, a person shall be considered to have been unconditionally discharged or released from active military, naval, air, or space service when the following conditions are met:
(1) The person served in the active military, naval, air, or space service for the period of time the person was obligated to serve at the time of entry into service;
(2) The person was not discharged or released from such service at the time of completing that period of obligation due to an intervening enlistment or reenlistment; and
(3) The person would have been eligible for a discharge or release under conditions other than dishonorable at that time except for the intervening enlistment or reenlistment.