Second lieutenant (O-1)
Second lieutenant, pay grade O-1: the entry rank for commissioned officers in the US Air Force. The insignia is a single gold bar.
Easily confused with
How to read it
Second lieutenant is the most junior commissioned grade, below first lieutenant, whose single bar is silver: only the metal tells the two apart. It is the first of the company grade ranks, O-1 to O-3. The abbreviation is 2d Lt. The Army, Marine Corps and Space Force use the same grade, and the Navy’s equivalent is ensign (10 U.S.C. 741).
Also searched as: 2d Lt, O-1 air force.
Ranks and insignia as the Department of the Air Force’s own instructions and pages set them out. Pay grades are the Department of Defense’s.
Gold bar or silver bar?
Gold is second lieutenant and silver is first lieutenant (the Air Force insignia in the National Air and Space Museum’s collection). On the OCP camouflage uniform, where Air Force rank insignia are spice brown, the Air Force’s dress instruction makes first lieutenant’s bar black, so the two still differ by colour.
Read next
More air Force ranks
The same shape elsewhere
Browse symbols drawn with lines.
Sources
- U.S. Military Rank Insignia, Resources: U.S. Military Rank Insignia (enlisted and officer insignia by paygrade), U.S. Department of Defense (defense.gov), Officer insignia table, Air Force; officer introduction
- 37 U.S.C. 201, Pay grades: assignment to; general rules, United States Code, 2023 edition, Title 37, § 201, U.S. Government Publishing Office, § 201(a)(1) table
- 10 U.S.C. 741, Rank: commissioned officers of the armed forces, United States Code, 2024 edition, Title 10, § 741, U.S. Government Publishing Office, § 741(a) and its table
- Insignia, Rank, Second Lieutenant, United States Air Force, National Air and Space Museum, object A19951097000, Smithsonian National Air and Space Museum, Physical Description
- Insignia, Rank, First Lieutenant, United States Air Force, National Air and Space Museum, object A19951094000, Smithsonian National Air and Space Museum, Physical Description
- DAFI 36-2903, Dress and Personal Appearance of Air Force and Space Force Personnel, DAFI 36-2903, 29 February 2024, with guidance changes, Department of the Air Force, §5.1.3
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 30, 2026. How we research
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