33 U.S.C. § 3024
Promotion to fill vacancies in each permanent grade above the grade of lieutenant (junior grade) shall be made by selection from the next lower grade upon recommendation of the personnel board.
(Pub. L. 107–372, title II, § 224, , 116 Stat. 3085.)
Provisions similar to those in this section were contained in section 853b of this title prior to repeal by Pub. L. 107–372.