38 C.F.R. § 3.14

Service is valid unless the enlistment is voided by the service department.

(a) Enlistment not prohibited by statute. Where an enlistment is voided by the service department for reasons other than those stated in paragraph (b) of this section, service is valid from the date of entry upon active duty to the date of voidance by the service department. Benefits may not be paid, however, unless the discharge is held to have been under conditions other than dishonorable. Generally discharge for concealment of a physical or mental defect except incompetency or insanity which would have prevented enlistment will be held to be under dishonorable conditions.

(b) Statutory prohibition. Where an enlistment is voided by the service department because the person did not have legal capacity to contract for a reason other than minority (as in the case of an insane person) or because the enlistment was prohibited by statute (a deserter or person convicted of a felony), benefits may not be paid based on that service even though a disability was incurred during such service. An undesirable discharge by reason of the fraudulent enlistment voids the enlistment from the beginning.

(c) Misrepresentation of age. Active service which was terminated because of concealment of minority or misrepresentation of age is honorable if the veteran was released from service under conditions other than dishonorable. Service is valid from the date of entry upon active duty to the date of discharge.

(d) Honorable discharges. Determinations as to honorable service will be made by the service departments and the finding shall be binding on the Department of Veterans Affairs, but, in the case of an alien, the effect of the discharge will be governed by § 3.7(b).