§ 284. Regular Coast Guard; officers serving under temporary appointments
(a)
Each officer of the Regular Coast Guard appointed under section
214 of this title who is serving in the grade of lieutenant (junior grade) or lieutenant and who has failed of selection for promotion to the grade of lieutenant or lieutenant commander, respectively, for the second time shall:
(1)
be honorably discharged on June 30 of the promotion year in which his second failure of selection occurs; or
(b)
Each officer subject to discharge or retirement under subsection (a) may elect to revert to his permanent grade.