; and (ii) by inserting or 20241(c) after section 624(c) both places it appears. (8) Retirement for years of service (A) Lieutenant colonels Section 633(a) is amended— (i) by inserting (1) before Except as ; (ii) by striking Regular Marine Corps, or Regular Space Force and inserting or Regular Marine Corps ; and (iii) by adding at the end the following new paragraph: (2) Except as provided under section 637(b) or 637a of this title, each officer of the Space Force who holds the grade of lieutenant colonel who is not on a list of officers recommended for promotion to the grade of colonel shall, if not earlier retired, be retired on the first day of the month after the month in which the officer completes 28 years of active commissioned service. . (B) Colonels Section 634(a) is amended— (i) by inserting (1) before Except as ; (ii) by striking Regular Marine Corps, or Regular Space Force and inserting or Regular Marine Corps ; and (iii) by adding at the end the following new paragraph: (2) Except as provided under section 637(b) or 637a of this title, each officer of the Space Force who holds the grade of colonel who is not on a list of officers recommended for promotion to the grade of brigadier general shall, if not earlier retired, be retired on the first day of the month after the month in which the officer completes 30 years of active commissioned service. . (C) Brigadier generals Section 635 is amended— (i) by inserting (a) Army, navy, air force, and marine corps before Except as ; (ii) by striking Regular Marine Corps, or Regular Space Force and inserting or Regular Marine Corps