Branches of the U.S. Military
The U.S. military has six branches, which the U.S. Code calls the armed forces: “The term ‘armed forces’ means the Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard.” (10 U.S.C. 101(a)(4)).
Maintained by Archie Chang · Sources retrieved on November 2, 2026 (four pages through Internet Archive copies dated December 8, 2025, March 13, 2026, October 20, 2026, October 25, 2026; see Sources) · Methodology & sources
The six armed forces and their departments
“The term ‘armed forces’ means the Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard.”
| Branch | Department (as the statute says) | Date on the official page | Ranks |
|---|---|---|---|
| Army | Department of the Army |
| Army ranks |
| Navy | Department of the Navy |
| Navy ranks |
| Air Force | Department of the Air Force |
| Air Force ranks |
| Marine Corps | Department of the Navy |
| Marine Corps ranks |
| Space Force | Department of the Air Force |
| Space Force ranks |
| Coast Guard | Department of Homeland Security, except when operating as a service in the Navy |
| Coast Guard ranks |
For the Coast Guard, 14 U.S.C. 101 and the Coast Guard Historian’s Office give two different dates; both are shown with their sources.
In the subsections we saved, 10 U.S.C. 7062(b), 8062(a), 8063(a) and 9062(b), retrieved on November 2, 2026, the text gave no founding date for the Army, Navy, Marine Corps or Air Force, so those dates come from the service pages quoted below.
What the statutes and service pages say, branch by branch
Army
“In general, the Army, within the Department of the Army, includes land combat and service forces and such aviation and water transport as may be organic therein.”
“On June 14, 1775, the Second Continental Congress established the Continental Army, marking the beginning of what would become the United States Army.”
Navy
“The Navy, within the Department of the Navy, includes, in general, naval combat and service forces and such aviation as may be organic therein.”
“On Oct. 13, 1775, a resolution to commission a vessel of war by the Continental Congress established the foundation for what is now the United States Navy […]”
“In 1972, Chief of Naval Operations Adm. Elmo R. Zumwalt, Jr., officially authorized Oct. 13 as the Navy’s birthday […]”
“Acting on this authority, the Department of the Navy was established on April 30, 1798.”
Air Force
“There is a United States Air Force within the Department of the Air Force.”
“On July 26, 1947, President Harry S. Truman used this pen to sign the National Security Act of 1947 while aboard the Douglas VC-54C Sacred Cow, the first dedicated presidential aircraft. This act officially established the United States Air Force as a separate and co-equal branch of the United States Armed Forces on Sept. 18, 1947.”
Marine Corps
“The Marine Corps, within the Department of the Navy, shall be so organized as to include not less than three combat divisions and three air wings, and such other land combat, aviation, and other services as may be organic therein.”
“It was founded on November 10, 1775, by the Second Continental Congress during the American Revolution.”
“No, the United States Marine Corps is not part of the Navy, but it operates under the Department of the Navy.”
Space Force
“There is established a United States Space Force as an armed force within the Department of the Air Force.”
“Established on December 20, 2019, the United States Space Force is the sixth military branch in the U.S. Armed Forces.”
Coast Guard
“The Coast Guard shall be a service in the Department of Homeland Security, except when operating as a service in the Navy.”
“Upon the declaration of war if Congress so directs in the declaration or when the President directs, the Coast Guard shall operate as a service in the Navy, and shall so continue until the President, by Executive order, transfers the Coast Guard back to the Department of Homeland Security.”
“The Coast Guard, established January 28, 1915, shall be a military service and a branch of the armed forces of the United States at all times.”
“We trace our history to 4 August 1790, when the first Congress authorized the construction of ten vessels to enforce tariff and trade laws and to prevent smuggling.”
“The service received its present name in 1915 under an act of Congress when the Revenue Cutter Service merged with the Life-Saving Service.”
“The United States Coast Guard, one of the country's five armed services, is a unique agency of the federal government.”
Where the sources differ
The Coast Guard Historian’s Office page describes the Coast Guard as “one of the country's five armed services”, while 10 U.S.C. 101(a)(4) lists six armed forces, with the Space Force among them. The statute is the list used on this page.
The two Coast Guard dates describe different events the sources name: 14 U.S.C. 101 says “established January 28, 1915”, and the Historian’s Office says the service “received its present name in 1915” and traces its history to 4 August 1790.
The Army date comes from an article on army.mil by the Director of the Fort Jackson Museum Community, and the Navy dates from an issue of the Naval History and Heritage Command’s Navy History Matters. They are official sites, not statutes.
Armed forces and uniformed services
The same section of the U.S. Code defines the larger group of uniformed services:
“(5) The term ‘uniformed services’ means—
(A) the armed forces;
(B) the commissioned corps of the National Oceanic and Atmospheric Administration; and
(C) the commissioned corps of the Public Health Service.”
Six armed forces plus two commissioned corps makes eight uniformed services (arithmetic on the statute’s list). The statute also defines the military departments:
“The term ‘military departments’ means the Department of the Army, the Department of the Navy, and the Department of the Air Force.”
The National Guard is not one of the six armed forces in 10 U.S.C. 101(a)(4): in the text retrieved on November 2, 2026, that definition did not name it. We mention the National Guard because a reader may wonder whether it is a seventh branch; this page says nothing more about its status.
Related pages
Frequently asked questions
How many branches of the military are there?
Six. 10 U.S.C. 101(a)(4) says: “The term ‘armed forces’ means the Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard.” The Space Force’s own page calls it “the sixth military branch in the U.S. Armed Forces.”
What are the six branches and which department is each in?
Army: Department of the Army; Navy: Department of the Navy; Air Force: Department of the Air Force; Marine Corps: Department of the Navy; Space Force: Department of the Air Force; Coast Guard: Department of Homeland Security, except when operating as a service in the Navy. The department comes from 10 U.S.C. 7062(b), 8062(a), 8063(a), 9062(b) and 9081(a) and 14 U.S.C. 103(a).
Is the Coast Guard part of the military?
Yes. 14 U.S.C. 101 says: “The Coast Guard, established January 28, 1915, shall be a military service and a branch of the armed forces of the United States at all times.” 14 U.S.C. 103(a) says: “The Coast Guard shall be a service in the Department of Homeland Security, except when operating as a service in the Navy.” 14 U.S.C. 103(b) says: “Upon the declaration of war if Congress so directs in the declaration or when the President directs, the Coast Guard shall operate as a service in the Navy, and shall so continue until the President, by Executive order, transfers the Coast Guard back to the Department of Homeland Security.”
Is the Space Force part of the Air Force?
10 U.S.C. 9081(a) says: “There is established a United States Space Force as an armed force within the Department of the Air Force.” The statute calls the Space Force an armed force and places it within the Department of the Air Force.
Is the Marine Corps part of the Navy?
The Marine Corps’ own page says: “No, the United States Marine Corps is not part of the Navy, but it operates under the Department of the Navy.” 10 U.S.C. 8063(a) places the Marine Corps “within the Department of the Navy”.
Which branch is the oldest?
By the dates on the official pages we saved, the Army (June 14, 1775), Navy (Oct. 13, 1775) and Marine Corps (November 10, 1775) all date to 1775, in that order; that order is arithmetic on the three dates, not a ranking any source states. The Coast Guard Historian’s Office traces the Coast Guard’s history to 4 August 1790, while 14 U.S.C. 101 gives January 28, 1915 as the date the Coast Guard was established.
What is the difference between the armed forces and the uniformed services?
The armed forces are the six branches. 10 U.S.C. 101(a)(5) defines the uniformed services as the armed forces, the commissioned corps of the National Oceanic and Atmospheric Administration and the commissioned corps of the Public Health Service. Six armed forces plus two commissioned corps makes eight uniformed services (arithmetic on the statute’s list). The National Guard is not one of the six armed forces in 10 U.S.C. 101(a)(4): in the text retrieved on November 2, 2026, that definition did not name it. We mention the National Guard because a reader may wonder whether it is a seventh branch; this page says nothing more about its status.
Sources (retrieved November 2, 2026; four pages through Internet Archive copies dated December 8, 2025, March 13, 2026, October 20, 2026, October 25, 2026): 10 U.S.C. 101, Definitions · 10 U.S.C. 7062, Army: policy; composition · 10 U.S.C. 8062, Navy: composition; functions · 10 U.S.C. 8063, Marine Corps: composition; functions · 10 U.S.C. 9062, Air Force: policy; composition · 10 U.S.C. 9081, The United States Space Force · 14 U.S.C. 101, Establishment of Coast Guard · 14 U.S.C. 103, Department in which the Coast Guard operates · army.mil: The birth of the Army: Two and a half centuries of service · Naval History and Heritage Command: Navy History Matters, October 1, 2024 · U.S. Marine Corps: history page · National Museum of the United States Air Force: USAF Established · U.S. Space Force: anniversary page · U.S. Coast Guard Historian’s Office: History Overview
The official page for each of these was read through an Internet Archive copy, not directly from the agency’s site:
- Naval History and Heritage Command: Navy History Matters, October 1, 2024: official page https://www.history.navy.mil/news-and-events/news/2024/nhm-100124.html; Internet Archive copy of December 8, 2025: https://web.archive.org/web/20251208080857id_/https://www.history.navy.mil/news-and-events/news/2024/nhm-100124.html. The official address returned a 404 error when we checked on November 2, 2026.
- National Museum of the United States Air Force: USAF Established: official page https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/195791/usaf-established/; Internet Archive copy of March 13, 2026: https://web.archive.org/web/20260313143842id_/https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/195791/usaf-established/.
- U.S. Space Force: anniversary page: official page https://www.spaceforce.mil/anniversary/; Internet Archive copy of October 20, 2026: https://web.archive.org/web/20261020072934id_/https://www.spaceforce.mil/Anniversary/.
- U.S. Coast Guard Historian’s Office: History Overview: official page https://www.history.uscg.mil/home/history-program/; Internet Archive copy of October 25, 2026: https://web.archive.org/web/20261025111158id_/https://www.history.uscg.mil/home/history-program/.