# Captain (United States O-3)

Captain is the company-grade commissioned officer rank at pay grade O-3 in the [United States Army](https://www.edgepedia.org/united-states-army), Marine Corps, Air Force, and Space Force, abbreviated CPT in the Army and Capt in the other three services<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup>. In the Navy and Coast Guard the same pay grade is called [Lieutenant](https://www.edgepedia.org/lieutenant)<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup>, because in those sea services the title Captain is reserved for O-6, the equivalent of an Army colonel<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup>.

| Key fact | Detail |
|---|---|
| Pay grade | O-3, the third of ten commissioned-officer grades (O-1 through O-10)<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup> |
| Services using the title | Army (CPT), Marine Corps (Capt), Air Force (Capt), Space Force (Capt)<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup> |
| Navy and Coast Guard equivalent | Lieutenant (LT)<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup> |
| Insignia | Two silver bars; O-1 wears one gold bar and O-2 one silver bar<sup>[2](https://www.militaryonesource.mil/military-basics/new-to-the-military/military-insignia-what-are-those-stripes-and-bars/)</sup> |
| Officer category | Company grade, covering pay grades O-1 to O-3, below field grade (O-4 to O-6) and general officers (O-7 and above)<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup> |
| Monthly basic pay | $5,331.60 at 2 years of service or less, rising to $8,674.50 at over 14 years<sup>[3](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm)</sup> |
| NATO code | OF-2, the same code as a British Army Captain or RAF Flight Lieutenant<sup>[4](https://www.gov.uk/government/publications/uk-armed-forces-equal-pay-audit-2020-to-2021/uk-armed-forces-equal-pay-audit-2020-to-2021)</sup> |
| Typical Army timing | Promotion to CPT noted at about 3 years, 11 months of service<sup>[5](https://www.army.mil/e2/downloads/rv7/about/ARMY_101.pdf)</sup> |

## Rank structure and insignia

Commissioned officers hold the highest ranks in the military; they hold presidential commissions and are confirmed at their ranks by the Senate<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup>. Within that group, Army, Air Force, and Marine Corps officers in pay grades O-1 to O-3 are called company grade officers, O-4 to O-6 field grade officers, and O-7 and above general officers; the Navy groups its equivalents as junior grade, mid-grade, and flag instead<sup>[1](https://www.defense.gov/Resources/Insignia/Military-Ranks/)</sup>.

The two silver bars of an O-3 follow a bar sequence that runs one gold bar at O-1, one silver bar at O-2, and two silver bars at O-3, with gold oak leaves at O-4, silver oak leaves at O-5, and silver eagles at O-6<sup>[2](https://www.militaryonesource.mil/military-basics/new-to-the-military/military-insignia-what-are-those-stripes-and-bars/)</sup>. In address, an Army, Marine Corps, or Air Force captain is spoken to as "Captain" and last name<sup>[2](https://www.militaryonesource.mil/military-basics/new-to-the-military/military-insignia-what-are-those-stripes-and-bars/)</sup>.

## Pay and promotion rules

Basic pay for O-3 officers is set in Title 37 of the [United States Code](https://www.edgepedia.org/united-states-code) and rises with cumulative years of service. In the 2024 statutory table, monthly basic pay was $5,331.60 at two years of service or less, $6,044.10 at over two years, $6,522.60 at over three, $7,112.40 at over four, $7,453.80 at over six, $7,827.90 at over eight, $8,069.10 at over ten, $8,466.60 at over twelve, and $8,674.50 at over fourteen, where it plateaus<sup>[3](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm)</sup>. A special rule applies to O-1, O-2, and O-3 officers credited with more than four years of active-duty service as an enlisted member or warrant officer: their pay is computed as if they had that much additional active commissioned service<sup>[3](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm)</sup>.

Promotion law also treats the grade as a career gate. A reserve officer of the Army, Air Force, or Marine Corps holding a permanent appointment in the grade of captain may not be considered for promotion to the next higher grade until completing three years of service in grade<sup>[6](https://uscode.house.gov/view.xhtml?edition=prelim&path=%2Fprelim%40title10%2FsubtitleE%2Fpart3)</sup>.

## Why the Army and Navy captains differ

The same word describes an O-3 in the land services and an O-6 in the Navy because the two services grew the title in different directions. When the [Continental Congress](https://www.edgepedia.org/continental-congress) created the [Continental Army](https://www.edgepedia.org/continental-army) in 1775, the first officer ranks it authorized were Captain, Major, and Colonel, drawn from British models, with Lieutenant added soon after<sup>[7](https://www.historyrise.com/article/the-history-of-officer-ranks-in-the-united-states-armed-forces/)</sup>. Within the Navy, Captain stood as the senior rank from the service's founding in 1775 up to 1857, at which point Congress established Flag Officer as a temporary rank, later replaced by Commodore and Rear Admiral in 1862.<sup>[8](https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/w/naval-traditions-names-of-rank/officer/navy-captain.html)</sup>

Early naval regulations show the split already forming. A 1776 equivalence plan, partially adopted, graded a captain of a 40-gun ship and upward to rank with a colonel, a captain of a 20- to 40-gun ship to rank with a lieutenant colonel, a captain of a 10- to 20-gun ship to rank with a major, and a lieutenant to rank with a captain in the Army<sup>[9](https://www.usna.edu/Ethics/_files/documents/SLA%20Marshall%20Armed%20Forces%20Officer.pdf)</sup>. In 1779 the naval grade of Captain was very inclusive: any commissioned officer in command of a warship was a permanent Captain<sup>[10](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)</sup>. To distinguish rank within that grade, the Navy later restricted the rank of Captain to commanding officers of ships with forty or more guns; commanders of 20- to 40-gun ships became Master Commandant, then [Commander](https://www.edgepedia.org/commander) in 1837, and commanders of 10- to 20-gun ships became Lieutenants Commanding, then Lieutenant Commander in 1862<sup>[10](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)</sup>. The naval [Lieutenant](https://www.edgepedia.org/lieutenant-navy) has usually been equated with the land Captain, which is the pairing still in force at O-3 today<sup>[10](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)</sup>.

## Civilian and international comparisons

Under federal grade-mapping tables, the O-3 naval rank of Lieutenant corresponds to civilian grade GS-11<sup>[11](https://www.jwc.nato.int/wp-content/uploads/2024/08/ifib023049jwc_v3_1.pdf)</sup>. In the NATO rank-code system, the US O-3 captain corresponds to OF-2, the same code as a British Army Captain or RAF Flight Lieutenant<sup>[4](https://www.gov.uk/government/publications/uk-armed-forces-equal-pay-audit-2020-to-2021/uk-armed-forces-equal-pay-audit-2020-to-2021)</sup>.

## References

1. [U.S. Military Rank Insignia, Department of Defense](https://www.defense.gov/Resources/Insignia/Military-Ranks/)
2. [Military Insignia: What Are Those Stripes and Bars?, Military OneSource](https://www.militaryonesource.mil/military-basics/new-to-the-military/military-insignia-what-are-those-stripes-and-bars/)
3. [U.S.C. Title 37, Pay and Allowances of the Uniformed Services, govinfo](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm)
4. [UK armed forces equal pay audit 2020 to 2021, GOV.UK](https://www.gov.uk/government/publications/uk-armed-forces-equal-pay-audit-2020-to-2021/uk-armed-forces-equal-pay-audit-2020-to-2021)
5. [Rank Insignia of Your Army, U.S. Army (ARMY_101.pdf)](https://www.army.mil/e2/downloads/rv7/about/ARMY_101.pdf)
6. [10 U.S.C., Officers in Pay Grades O-3 and Above, uscode.house.gov](https://uscode.house.gov/view.xhtml?edition=prelim&path=%2Fprelim%40title10%2FsubtitleE%2Fpart3)
7. [The History of Officer Ranks in the United States Armed Forces, History Rise](https://www.historyrise.com/article/the-history-of-officer-ranks-in-the-united-states-armed-forces/)
8. [Navy Captain, Naval History and Heritage Command](https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/w/naval-traditions-names-of-rank/officer/navy-captain.html)
9. [The Armed Forces Officer, S.L.A. Marshall, U.S. Naval Academy](https://www.usna.edu/Ethics/_files/documents/SLA%20Marshall%20Armed%20Forces%20Officer.pdf)
10. [From Admiral To Midshipman, Lt. Richard H. Sprince, USNI Proceedings, November 1956](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)
11. [NATO UNCLASSIFIED grade mapping, JWC](https://www.jwc.nato.int/wp-content/uploads/2024/08/ifib023049jwc_v3_1.pdf)

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*Topic: Encyclopedia › Society and history › Conflict and security › Ranks, honours, and service traditions › Military ranks › Ranks by country › United States rank system*

*Initially written Sep 17, 2026 · Reviewed: Sep 17, 2026; Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*

*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*

License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license