§ 309. Federal recognition of National Guard officers: officers promoted to fill vacancies
Each officer of the National Guard who is promoted to fill a vacancy in a federally recognized unit of the National Guard, and who has been on the reserve active-status list or the active-duty list of the Army or the Air Force for at least one year and has completed the minimum years of service in grade specified in section
14303 of title
10, shall be examined for Federal recognition in the grade to which the officer is promoted.