# § 634. Retirement for years of service: regular and Space Force colonels; regular Navy captains
**(a)** **30 Years of Active Commissioned Service.—**
**(1)** Except as provided in subsection (b) and as provided under section 637(b) or 637a of this title, each officer of the Regular Army, Regular Air Force, or Regular Marine Corps who holds the regular grade of colonel, and each officer of the Regular Navy who holds the regular grade of captain, who is not on a list of officers recommended for promotion to the regular grade of brigadier general or rear admiral (lower half), respectively, shall, if not earlier retired, be retired on the first day of the month after the month in which he completes 30 years of active commissioned service.
**(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.
**(b)** **Exceptions.—** Subsection (a) does not apply to the following:
**(1)** An officer of the Navy who is designated for limited duty to whom section 8372(a)(4) of this title applies.
**(2)** An officer of the Navy or Marine Corps who is a permanent professor at the United States Naval Academy.
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**Source Credit**: (Added Pub. L. 96–513, title I, § 105, Dec. 12, 1980, 94 Stat. 2862; amended Pub. L. 97–86, title IV, § 405(b)(1), Dec. 1, 1981, 95 Stat. 1105; Pub. L. 98–525, title XIV, § 1405(13), Oct. 19, 1984, 98 Stat. 2622; Pub. L. 99–145, title V, § 514(b)(1), Nov. 8, 1985, 99 Stat. 628; Pub. L. 102–484, div. A, title V, § 504(b), Oct. 23, 1992, 106 Stat. 2403; Pub. L. 103–160, div. A, title V, § 561(e), Nov. 30, 1993, 107 Stat. 1667; Pub. L. 105–261, div. A, title V, § 504(b), Oct. 17, 1998, 112 Stat. 2004; Pub. L. 109–163, div. A, title V, § 509(a)(2), Jan. 6, 2006, 119 Stat. 3229; Pub. L. 114–328, div. A, title V, § 505(b)(2), Dec. 23, 2016, 130 Stat. 2108; Pub. L. 115–232, div. A, title VIII, § 809(a), Aug. 13, 2018, 132 Stat. 1840; Pub. L. 116–283, div. A, title IX, § 924(b)(4)(E), Jan. 1, 2021, 134 Stat. 3822; Pub. L. 118–31, div. A, title XVII, § 1722(b)(6)(B), (E)(ii), Dec. 22, 2023, 137 Stat. 669, 670.)
## Editorial Notes
### Amendments
2023—, substituted “and Space Force colonels; regular” for “colonels and” in section catchline.
Subsec. (a). , designated existing provisions as par. (1), substituted “or Regular Marine Corps” for “Regular Marine Corps, or Regular Space Force”, and added par. (2).
2021—Subsec. (a). substituted “Regular Marine Corps, or Regular Space Force” for “or Regular Marine Corps”.
2018—Subsec. (b)(1). substituted “section 8372(a)(4)” for “section 6383(a)(4)”.
2016—Subsec. (a). inserted “or 637a” after “637(b)”.
2006— designated existing provisions as subsec. (a), inserted heading, substituted “Except as provided in subsection (b) and as provided” for “Except an officer of the Navy who is designated for limited duty to whom applies and except as provided”, and added subsec. (b).
1998— inserted “an officer of the Navy who is designated for limited duty to whom applies and except” after “Except” and struck out at end “During the period beginning on , and ending on , the preceding sentence shall not apply to an officer of the Regular Navy designated for limited duty to whom applies.”
1993— substituted “” for “”.
1992— inserted at end “During the period beginning on , and ending on , the preceding sentence shall not apply to an officer of the Regular Navy designated for limited duty to whom applies.”
1985— substituted “rear admiral (lower half)” for “commodore”.
1984— substituted “30” for “thirty”.
1981— substituted “commodore” for “commodore admiral”.
## Statutory Notes and Related Subsidiaries
### Effective Date of 2018 Amendment
Amendment by effective , with provision for the coordination of amendments and special rule for certain redesignations, see , set out as a note preceding .
### Effective Date of 1981 Amendment
Amendment by effective , see , set out as a note under .
### Effective Date
Section effective , but the authority to prescribe regulations under this section effective on , see , set out as an Effective Date of 1980 Amendment note under .