10 U.S.C. § 630: Discharge of commissioned officers with less than six years of active commissioned service or found not qualified for promotion for first lieutenant or lieutenant (junior grade)

The Secretary of the military department concerned, under regulations prescribed by the Secretary of Defense—(1) may discharge any officer on the active-duty list who—(A) has less than six years of active commissioned service; or (B) is serving in the grade of second lieutenant or ensign and has been found not qualified for promotion to the grade of first lieutenant or lieutenant (junior grade); and (2) shall, unless the officer has been promoted, discharge any officer described in paragraph (1)(B) at the end of the 18-month period beginning on the date on which the officer is first found not qualified for promotion.