(a) Retention.— Notwithstanding the provisions of section
14506,
14507, or
14508 of this title, the Secretary of the military department concerned may, with the officers consent, retain on the reserve active-status list an officer in the grade of major, lieutenant colonel, colonel, or brigadier general who is
(1) an officer of the Army National Guard of the United States and assigned to a headquarters or headquarters detachment of a State; or
(2) a reserve officer of the Army or Air Force who, as a condition of continued employment as a National Guard or Reserve technician is required by the Secretary concerned to maintain membership in a Selected Reserve unit or organization.