14 U.S.C. § 3736

(a) Reserve officers rank and take precedence in their respective grades among themselves and with officers of the same grade on the active duty promotion list, officers designated by the Secretary pursuant to this section, and the officers on the permanent commissioned teaching staff in accordance with their dates of rank. When Reserve officers and officers on the active duty promotion list, officers designated by the Secretary pursuant to this section, or the officers on the permanent commissioned teaching staff have the same date of rank in a grade, they take prec­edence as determined by the Secretary. (b) Notwithstanding any other law, a Reserve officer shall not lose precedence when transferred to or from the active duty promotion list, nor shall that officer’s date of rank be changed due to the transfer. (c) A Reserve officer shall, when on the active duty promotion list, be promoted in the same manner as any other officer on the active duty promotion list regardless of the length of active duty service of the Reserve officer. (d) Notwithstanding any other law, a Reserve officer shall not lose precedence by reason of promotion to the grade of rear admiral or rear admiral (lower half), if the promotion is determined in accordance with a running mate system. (e) The Secretary shall adjust the date of rank of a Reserve officer so that no changes of precedence occur.