14 U.S.C. § 251 : US Code - Section 251: Selection boards; convening of boards

Search 14 U.S.C. § 251 : US Code - Section 251: Selection boards; convening of boards

At least once a year and at such other times as the needs of the
service require, the Secretary shall convene selection boards to
recommend for promotion to the next higher grade officers on the
active duty promotion list in each grade from lieutenant (junior
grade) through captain, with separate boards for each grade.
However, the Secretary is not required to convene a board to
recommend officers for promotion to a grade when no vacancies exist
in the grade concerned, and he estimates that none will occur in
the next twelve months.