14 U.S.C. § 737 - Type of promotion; temporary

Notwithstanding any other law, if a Reserve officer is promoted when the officers running mate is promoted and the promotion of the running mate is on a temporary basis, the promotion of the Reserve officer is also on a temporary basis. If subsequently the running mate is reverted to a lower grade, other than for reasons of discipline, incompetence, or at the running mates request, the Reserve officer shall likewise revert to the same lower grade with corresponding precedence.