|Uniformed services of the United States|
|Founded||14 June 1775 [lower-alpha 1]|
|Federal department heads|
|Military age||17 with parental consent, 18 for voluntary service. [lower-alpha 2]|
|Conscription||Male only (inactive since 1973)|
|17 million  , age 18–25 (2016)|
|2 million  (2016)|
|Active personnel||1,374,125  (ranked 3rd)|
|Reserve personnel||849,450 |
|Deployed personnel||170,000[ citation needed ]|
|Budget||US$721.5 billion (2020)  (ranked 1st)|
|Percent of GDP||3.42% (2019) |
|History|| Military history of the United States |
List of engagements
American Revolutionary War
Las Cuevas War
Persian Gulf War
Military deployment after Hurricane Katrina
The United States has eight federal uniformed services that commission officers as defined by Title 10 and subsequently structured and organized by Titles 10, 14, 32, 33 and 42 of the U.S. Code.
The uniformed services are, in order of precedence: 
Each of the uniformed services is administratively headed by a federal executive department and its corresponding civilian Cabinet leader.
Department of the Army (DA)
Department of the Navy (DON)
Department of the Air Force (DAF)
The order of precedence within the Department of Defense is set by DoD Directive 1005.8 and is not dependent on the date of creation by the U.S. Congress.
Prior to 1967, the Coast Guard was a part of the Department of the Treasury. In 1967, it became a part of the Department of Transportation. In 2002, it was placed under the Department of Homeland Security. During times of war, it may be transferred to the Department of the Navy, under the Department of Defense.
The Corps is headed by the Surgeon General of the United States.
The NOAA Corps was created as the United States Coast and Geodetic Survey Corps, a component of the United States Coast and Geodetic Survey, on 22 May 1917. It was removed from the Coast and Geodetic Survey and became a component of the Environmental Science Services Administration (ESSA) as the Environmental Science Services Administration Corps (ESSA Corps) upon the establishment of ESSA on 13 July 1965. The ESSA Corps became the NOAA Corps as a component of NOAA when ESSA was abolished and NOAA simultaneously was created on 3 October 1970. Under all three names, the corps has been an element of the Department of Commerce throughout its existence.
The eight uniformed services are defined by 10 U.S.C. § 101(a)(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.
The six uniformed services that make up the armed forces of the United States are defined in the previous clause, 10 U.S.C. § 101(a)(4) :
The term "armed forces" means the Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard.
All eight uniformed services are subject to the provisions of 10 USC 1408, the Uniformed Services Former Spouses' Protection Act. 
Six of the uniformed services make up the armed forces as defined by Title 10, five of which are within the Department of Defense. The Coast Guard is part of the Department of Homeland Security and has both military and law enforcement duties. Title 14 states that the Coast Guard is part of the armed forces at all times, making it the only branch of the military outside the Department of Defense. During a declared state of war, however, the President of the United States or U.S. Congress may direct that the Coast Guard operate as part of the Department of the Navy.  The Public Health Service Commissioned Corps, along with the NOAA Commissioned Corps, operate under military rules with the exception of the applicability of the Uniform Code of Military Justice, to which they are subject only when militarized by executive order or while detailed to any component of the armed forces. 
Reserve components of the United States Armed Forces are all members of the military who serve in a reserve capacity. The National Guard is an additional reserve military component of the Army and Air Force, respectively, and is composed of National Guard units, which operate under Title 32 and under state authority as the Army National Guard and Air National Guard. The militia that later became the National Guard was first formed in the Colony of Virginia in 1607 and is the oldest uniformed military force founded in the New World. The National Guard can also be mobilized by the president to operate under federal authority through Title 10. When acting under federal direction, the National Guard is managed by the National Guard Bureau, which is a joint Army and Air Force activity under the Department of Defense,    with a 4-star general   from the Army or Air Force appointed as its top leader. However, in federal service, command and control of National Guard organizations will fall under the designated geographic or functional combatant commander. The National Guard of the United States serves as a reserve component for both the Army and the Air Force, and can be called up for federal active duty in times of war or national emergencies.  
Commissioned officers of the NOAA Corps and PHSCC wear uniforms that are derived from U.S. Navy and Coast Guard uniforms, except that the commissioning devices, buttons, and insignia reflect their specific service. Uniformed officers of the NOAA Corps and PHSCC are paid on the same scale as members of the armed services, with respective rank and time-in-grade. Additionally, PHSCC officers are covered by the Uniformed Services Employment and Re-employment Rights Act and the Servicemembers Civil Relief Act (formerly the Soldiers and Sailors Civil Relief Act). The NOAA Corps and PHSCC consist of commissioned officers only and have no warrant officer ranks or enlisted ranks.
Commissioned officers of the NOAA Corps and PHSCC may be militarized by the president.  Because they are commissioned officers, they can be classified as prisoners of war under the Geneva Conventions if captured by a belligerent entity. The PHSCC traces its origins to a system of marine hospitals created by An Act for the relief of sick and disabled seamen, passed by Congress in 1798; it adopted a military model of organization in 1871.   The Coast and Geodetic Survey (USC&GS), a predecessor to NOAA, originally began commissioning its officers so that if captured while engaged in battlefield surveying, they would be protected under the law of armed conflict and could not be tried or executed as spies. The USC&GS Commissioned Officer Corps became the Environmental Science Services Administration Corps (ESSA Corps), upon the creation of the Environmental Science Services Administration on 13 July 1965, then became the NOAA Corps upon the creation of NOAA on 3 October 1970.
The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the commander-in-chief of the armed forces and forms military policy with the Department of Defense (DoD) and Department of Homeland Security (DHS), both federal executive departments, acting as the principal organs by which military policy is carried out. All six armed services are among the eight uniformed services of the United States.
The National Oceanic and Atmospheric Administration Commissioned Officer Corps, known informally as the NOAA Corps, is one of eight federal uniformed services of the United States, and operates under the National Oceanic and Atmospheric Administration (NOAA), a scientific agency overseen by the Department of Commerce. The NOAA Corps is made up of scientifically and technically trained officers. The NOAA Corps and the United States Public Health Service Commissioned Corps are the only U.S. uniformed services that consist only of commissioned officers, with no enlisted or warrant officer ranks. The NOAA Corps' primary mission is to monitor oceanic conditions, support major waterways, and monitor atmospheric conditions.
Lieutenant junior grade is a junior commissioned officer rank used in a number of navies.
The United States service academies, also known as the United States military academies, are federal academies for the undergraduate education and training of commissioned officers for the United States Armed Forces.
The Uniform Code of Military Justice (UCMJ) is the foundation of the system of military justice of the armed forces of the United States. The UCMJ was established by the United States Congress in accordance with their constitutional authority, per Article I, Section 8, which provides that "The Congress shall have Power. .. to make Rules for the Government and Regulation of the land and naval forces" of the United States.
Ensign is a junior rank of a commissioned officer in the armed forces of some countries, normally in the infantry or navy. As the junior officer in an infantry regiment was traditionally the carrier of the ensign flag, the rank acquired the name. This rank has generally been replaced in army ranks by second lieutenant. Ensigns were generally the lowest-ranking commissioned officer, except where the rank of subaltern existed. In contrast, the Arab rank of ensign, لواء, liwa', derives from the command of units with an ensign, not the carrier of such a unit's ensign, and is today the equivalent of a major general.
A 5⁄16 inch star (9.7mm) is a miniature gold or silver five-pointed star that is authorized by the United States Armed Forces as a ribbon device to denote subsequent awards for specific decorations of the Department of the Navy, Coast Guard, Public Health Service, and National Oceanic and Atmospheric Administration. A gold star indicates a second or subsequent decoration, while a silver star is worn in lieu of five gold stars.
The diver insignia are qualification badges of the uniformed services of the United States which are awarded to servicemen qualified as divers. Originally, the diver insignia was a cloth patch decoration worn by United States Navy divers in the upper-portion of the enlisted service uniform's left sleeve during the first part of World War II, when the rating insignia was worn on the right sleeve. When enlisted rating insignia were shifted to the left sleeve in late World War II, the patch shifted to the upper right sleeve. The diving patch was created during World War II, and became a breast insignia in the late 1960s.
The colonel in the United States Army, Marine Corps, Air Force and Space Force, is the most senior field-grade military officer rank, immediately above the rank of lieutenant colonel and just below the rank of brigadier general. Colonel is equivalent to the naval rank of captain in the other uniformed services. By law, an officer previously required at least 22 years of cumulative service and a minimum of three years as a lieutenant colonel before being promoted to colonel. With the signing of the National Defense Authorization Act of 2019, military services now have the authorization to directly commission new officers up to the rank of colonel. The pay grade for colonel is O-6.
Pay grades are used by the eight uniformed services of the United States to determine wages and benefits based on the corresponding military rank of a member of the services. While different ranks may be used among the eight uniformed services, pay grades are uniform and equivalent between the services and can be used to quickly determine seniority among a group of members from different services. They are also essential when determining a member's entitlements such as basic pay and allowances.
In the United States uniformed services, captain is a commissioned-officer rank. In keeping with the traditions of the militaries of most nations, the rank varies between the services, being a senior rank in the naval services and a junior rank in the ground and air forces. Many fire departments and police departments in the United States also use the rank of captain as an officer in a specific unit.
A direct commission officer (DCO) is a United States uniformed officer who has received an appointed commission without the typical prerequisites for achieving a commission, such as attending a four-year service academy, a four-year or two-year college ROTC program, or one of the officer candidate school or officer training school programs, the latter OCS/OTS programs typically slightly over three months in length.
The Environmental Science Services Administration (ESSA) was a United States Federal executive agency created in 1965 as part of a reorganization of the United States Department of Commerce. Its mission was to unify and oversee the meteorological, climatological, hydrographic, and geodetic operations of the United States. It operated until 1970, when it was replaced by the new National Oceanic and Atmospheric Administration (NOAA).
Lieutenant commander (LCDR) is a senior officer rank in the United States Navy, the United States Coast Guard, the United States Public Health Service Commissioned Corps, and the National Oceanic and Atmospheric Administration Commissioned Officer Corps, with the pay grade of O-4 and NATO rank code OF-3. Lieutenant commanders rank above lieutenants and below commanders. The rank is also used in the United States Maritime Service. The rank is equivalent to a major in the United States Army, United States Air Force, United States Marine Corps, and United States Space Force.
The United States Coast and Geodetic Survey, known from 1807 to 1836 as the Survey of the Coast and from 1836 until 1878 as the United States Coast Survey, was the first scientific agency of the United States Government. It existed from 1807 to 1970, and throughout its history was responsible for mapping and charting the coast of the United States, and later the coasts of U.S. territories. In 1871, it gained the additional responsibility of surveying the interior of the United States and geodesy became a more important part of its work, leading to it being renamed the U.S. Coast and Geodetic Survey in 1878.
An officer is a person who holds a position of authority as a member of an armed force or uniformed service.
In the United States Navy, United States Coast Guard, United States Public Health Service Commissioned Corps (USPHS), and National Oceanic and Atmospheric Administration Commissioned Officer Corps, captain is the senior-most commissioned officer rank below that of flag officer. The equivalent rank is colonel in the United States Army, Air Force, Space Force, and Marine Corps.
Rear Admiral James C. Tison Jr. was an officer in the United States Coast and Geodetic Survey Corps and Environmental Science Services Administration Corps, both predecessors of the National Oceanic and Atmospheric Administration Commissioned Officer Corps. He served simultaneously as the first Director of the ESSA Corps, one of only two people to hold the position, and as the sixth Director of the United States Coast and Geodetic Survey.
Rear Admiral Don A. Jones was an officer in the United States Coast and Geodetic Survey Corps, its successor, the Environmental Science Services Administration Corps, and the ESSA Corps's successor, the National Oceanic and Atmospheric Administration Commissioned Officer Corps. He served simultaneously as the second and last Director of the ESSA Corps, one of only two people to hold the position, and as the seventh and last Director of the United States Coast and Geodetic Survey.
Rear Admiral Harley Dean Nygren was an American military officer who served in the United States Coast and Geodetic Survey Corps, its successor, the Environmental Science Services Administration Corps, and the ESSA Corps's successor, the National Oceanic and Atmospheric Administration Commissioned Officer Corps. He served as the first Director of the NOAA Corps.