; authorized delay of promotions. 20231. Eligibility for consideration for promotion: time-in-grade and other requirements (a) Time-in-grade requirements (1) An officer who is in a Space Force active status on the Space Force officer list and holds a permanent appointment in the grade of second lieutenant or first lieutenant may not be promoted to the next higher permanent grade until the officer has completed the following period of service in the grade in which the officer holds a permanent appointment: (A) Eighteen months, in the case of an officer holding a permanent appointment in the grade of second lieutenant. (B) Two years, in the case of an officer holding a permanent appointment in the grade of first lieutenant. (2) Subject to paragraph (5), an officer who is in a Space Force active status on the Space Force officer list and holds a permanent appointment in a grade above first lieutenant may not be considered for selection for promotion to the next higher permanent grade until the officer has completed the following period of service in the grade in which the officer holds a permanent appointment: (A) Three years, in the case of an officer holding a permanent appointment in the grade of captain, major, or lieutenant colonel. (B) One year, in the case of an officer holding a permanent appointment in the grade of colonel or brigadier general. (3) When the needs of the service require, the Secretary of the Air Force may prescribe a longer period of service in grade for eligibility for promotion, in the case of officers to whom paragraph (1) applies, or for eligibility for consideration for promotion, in the case of officers to whom paragraph (2) applies. (4) When the needs of the service require, the Secretary of the Air Force may prescribe a shorter period of service in grade, but not less than two years, for eligibility for consideration for promotion, in the case of officers designated for limited duty to whom paragraph (2) applies. (5) The Secretary of the Air Force may waive paragraph (2) to the