10 U.S.C. § 101 — Definitions

**(a) In General.—** The following definitions apply in this title: (1) The term “United States”, in a geographic sense, means the States and the District of Columbia. (2) Repealed. Pub. L. 109–163, div. A, title X, § 1057(a)(1), Jan. 6, 2006, 119 Stat. 3440.] (3) The term “possessions” includes the Virgin Islands, Guam, American Samoa, and the Guano Islands, so long as they remain possessions, but does not include any Commonwealth. (4) The term “armed forces” means the Army, Navy, Air Force, Marine Corps, Space Force, and Coast Guard. (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. (6) The term “department”, when used with respect to a military department, means the executive part of the department and all field headquarters, forces, reserve components, installations, activities, and functions under the control or supervision of the Secretary of the department. When used with respect to the Department of Defense, such term means the executive part of the department, including the executive parts of the military departments, and all field headquarters, forces, reserve components, installations, activities, and functions under the control or supervision of the Secretary of Defense, including those of the military departments. (7) The term “executive part of the department” means the executive part of the Department of Defense, Department of the Army, Department of the Navy, or Department of the Air Force, as the case may be, at the seat of government. (8) The term “military departments” means the Department of the Army, the Department of the Navy, and the Department of the Air Force. (9) The term “Secretary concerned” means— (A) the Secretary of the Army, with respect to matters concerning the Army; (B) the Secretary of the Navy, with respect to matters concerning the Navy, the Marine Corps, and the Coast Guard when it is operating as a service in the Department of the Navy; (C) the Secretary of the Air Force, with respect to matters concerning the Air Force and the Space Force; and (D) the Secretary of Homeland Security, with respect to matters concerning the Coast Guard when it is not operating as a service in the Department of the Navy. (10) The term “service acquisition executive” means the civilian official within a military department who is designated as the service acquisition executive for purposes of regulations and procedures providing for a service acquisition executive for that military department. (11) The term “Defense Agency” means an organizational entity of the Department of Defense— (A) that is established by the Secretary of Defense under [section 191 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section191&num=0&edition=prelim) (or under the second sentence of [section 125(d) of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section125/d&num=0&edition=prelim) (as in effect before October 1, 1986)) to perform a supply or service activity common to more than one military department (other than such an entity that is designated by the Secretary as a Department of Defense Field Activity); or (B) that is designated by the Secretary of Defense as a Defense Agency. (12) The term “Department of Defense Field Activity” means an organizational entity of the Department of Defense— (A) that is established by the Secretary of Defense under [section 191 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section191&num=0&edition=prelim) (or under the second sentence of [section 125(d) of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section125/d&num=0&edition=prelim) (as in effect before October 1, 1986)) to perform a supply or service activity common to more than one military department; and (B) that is designated by the Secretary of Defense as a Department of Defense Field Activity. (13) The term “contingency operation” means a military operation that— (A) is designated by the Secretary of Defense as an operation in which members of the armed forces are or may become involved in military actions, operations, or hostilities against an enemy of the United States or against an opposing military force; or (B) results in the call or order to, or retention on, active duty of members of the uniformed services under section 688, 12301(a), 12302, 12304, 12304a, 12305, or 12406 of this title, chapter 13 of this title, [section 3713 of title 14](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title14-section3713&num=0&edition=prelim), or any other provision of law during a war or during a national emergency declared by the President or Congress. (14) The term “supplies” includes material, equipment, and stores of all kinds. (15) The term “pay” includes basic pay, special pay, retainer pay, incentive pay, retired pay, and equivalent pay, but does not include allowances. (16) The term “congressional defense committees” means— (A) the Committee on Armed Services and the Committee on Appropriations of the Senate; and (B) the Committee on Armed Services and the Committee on Appropriations of the House of Representatives. (17) The term “base closure law” means the following: (A) [Section 2687 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section2687&num=0&edition=prelim). (B) The Defense Base Closure and Realignment Act of 1990 (part A of title XXIX of Public Law 101–510; [10 U.S.C. 2687](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section2687&num=0&edition=prelim) note). (C) Title II of the Defense Authorization Amendments and Base Closure and Realignment Act (Public Law 100–526; [10 U.S.C. 2687](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section2687&num=0&edition=prelim) note). (18) The term “acquisition workforce” means the persons serving in acquisition positions within the Department of Defense, as designated pursuant to [section 1721(a) of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section1721/a&num=0&edition=prelim). (19) The term “climate resilience” means the capability to avoid, prepare for, minimize the effect of, adapt to, and recover from, extreme weather, or from anticipated or unanticipated changes in environmental conditions, that do (or have the potential to) adversely affect the national security of the United States or of allies and partners of the United States. (20) The term “extreme weather” means recurrent flooding, drought, desertification, wildfires, thawing permafrost, sea level fluctuation, changes in mean high tides, or any other weather-related event, or anticipated change in environmental conditions, that present (or are projected to present) a recurring annual threat to the climate security of the United States or of allies and partners of the United States. (21) The term “major weapon system” means a weapon system acquired pursuant to a major defense acquisition program (as that term is defined in [section 4201 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section4201&num=0&edition=prelim)). **(b) Personnel Generally.—** The following definitions relating to military personnel apply in this title: (1) The term “officer” means a commissioned or warrant officer. (2) The term “commissioned officer” includes a commissioned warrant officer. (3) The term “warrant officer” means a person who holds a commission or warrant in a warrant officer grade. (4) The term “general officer” means an officer of the Army, Air Force, Marine Corps, or Space Force serving in or having the grade of general, lieutenant general, major general, or brigadier general. (5) The term “flag officer” means an officer of the Navy or Coast Guard serving in or having the grade of admiral, vice admiral, rear admiral, or rear admiral (lower half). (6) The term “enlisted member” means a person in an enlisted grade. (7) The term “grade” means a step or degree, in a graduated scale of office or military rank, that is established and designated as a grade by law or regulation. (8) The term “rank” means the order of precedence among members of the armed forces. (9) The term “rating” means the name (such as “boatswain’s mate”) prescribed for members of an armed force in an occupational field. The term “rate” means the name (such as “chief boatswain’s mate”) prescribed for members in the same rating or other category who are in the same grade (such as chief petty officer or seaman apprentice). (10) The term “original”, with respect to the appointment of a member of the armed forces in a regular or reserve component, refers to that member’s most recent appointment in that component that is neither a promotion nor a demotion and, with respect to the appointment of a member of the armed forces in the Space Force, refers to that member’s most recent appointment in the Space Force that is neither a promotion nor a demotion. (11) The term “authorized strength” means the largest number of members authorized to be in an armed force, a component, a branch, a grade, or any other category of the armed forces. (12) The term “regular”, with respect to an enlistment, appointment, grade, or office, means enlistment, appointment, grade, or office in a regular component of an armed force. (13) The term “active-duty list” means a single list for the Army, Navy, Air Force, Marine Corps, or Space Force (required to be maintained under [section 620 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section620&num=0&edition=prelim)) which contains the names of all officers of that armed force, other than officers described in [section 641 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section641&num=0&edition=prelim), who are serving on active duty. (14) The term “medical officer” means an officer of the Medical Corps of the Army, an officer of the Medical Corps of the Navy, or an officer in the Air Force designated as a medical officer. (15) The term “dental officer” means an officer of the Dental Corps of the Army, an officer of the Dental Corps of the Navy, or an officer of the Air Force designated as a dental officer. (16) The term “Active Guard and Reserve” means a member of a reserve component who is on active duty pursuant to [section 12301(d) of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section12301/d&num=0&edition=prelim) or, if a member of the Army National Guard or Air National Guard, is on full-time National Guard duty pursuant to [section 502(f) of title 32](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title32-section502/f&num=0&edition=prelim), and who is performing Active Guard and Reserve duty. **(c) Reserve Components.—** The following definitions relating to the reserve components apply in this title: (1) The term “National Guard” means the Army National Guard and the Air National Guard. (2) The term “Army National Guard” means that part of the organized militia of the several States and Territories, Puerto Rico, and the District of Columbia, active and inactive, that— (A) is a land force; (B) is trained, and has its officers appointed, under the sixteenth clause of section 8, article I, of the Constitution; (C) is organized, armed, and equipped wholly or partly at Federal expense; and (D) is federally recognized. (3) The term “Army National Guard of the United States” means the reserve component of the Army all of whose members are members of the Army National Guard. (4) The term “Air National Guard” means that part of the organized militia of the several States and Territories, Puerto Rico, and the District of Columbia, active and inactive, that— (A) is an air force; (B) is trained, and has its officers appointed, under the sixteenth clause of section 8, article I, of the Constitution; (C) is organized, armed, and equipped wholly or partly at Federal expense; and (D) is federally recognized. (5) The term “Air National Guard of the United States” means the reserve component of the Air Force all of whose members are members of the Air National Guard. (6) The term “reserve”, with respect to an enlistment, appointment, grade, or office, means enlistment, appointment, grade, or office held as a Reserve of one of the armed forces. (7) The term “reserve active-status list” means a single list for the Army, Navy, Air Force, or Marine Corps (required to be maintained under [section 14002 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section14002&num=0&edition=prelim)) that contains the names of all officers of that armed force except warrant officers (including commissioned warrant officers) who are in an active status in a reserve component of the Army, Navy, Air Force, or Marine Corps and are not on an active-duty list. **(d) Duty Status.—** The following definitions relating to duty status apply in this title: (1) The term “active duty” means full-time duty in the active military service of the United States, including sustained duty in the Space Force. Such term includes full-time training duty, annual training duty, and attendance, while in the active military service, at a school designated as a service school by law or by the Secretary of the military department concerned. Such term does not include full-time National Guard duty. (2) The term “active duty for a period of more than 30 days” means active duty under a call or order that does not specify a period of 30 days or less. (3) The term “active service” means service on active duty or full-time National Guard duty. (4) The term “active status” means the status of a member of a reserve component who is not in the inactive Army National Guard or inactive Air National Guard, on an inactive status list, or in the Retired Reserve. (5) The term “full-time National Guard duty” means training or other duty, other than inactive duty, performed by a member of the Army National Guard of the United States or the Air National Guard of the United States in the member’s status as a member of the National Guard of a State or territory, the Commonwealth of Puerto Rico, or the District of Columbia under section 316, 502, 503, 504, or 505 of title 32 for which the member is entitled to pay from the United States or for which the member has waived pay from the United States. (6) (A) The term “active Guard and Reserve duty” means active duty performed by a member of a reserve component of the Army, Navy, Air Force, or Marine Corps, or full-time National Guard duty performed by a member of the National Guard pursuant to an order to full-time National Guard duty, for a period of 180 consecutive days or more for the purpose of organizing, administering, recruiting, instructing, or training the reserve components. (B) Such term does not include the following: (i) Duty performed as a member of the Reserve Forces Policy Board provided for under [section 10301 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section10301&num=0&edition=prelim). (ii) Duty performed as a property and fiscal officer under [section 708 of title 32](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title32-section708&num=0&edition=prelim). (iii) Duty performed for the purpose of interdiction and counter-drug activities for which funds have been provided under [section 112 of title 32](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title32-section112&num=0&edition=prelim). (iv) Duty performed as a general or flag officer. (v) Service as a State director of the Selective Service System under section 10(b)(2) of the Military Selective Service Act ([50 U.S.C. 3809(b)(2)](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title50-section3809/b/2&num=0&edition=prelim)). (7) The term “inactive-duty training” means— (A) duty prescribed for Reserves, or a member of the Space Force, by the Secretary concerned under [section 206 of title 37](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title37-section206&num=0&edition=prelim) or any other provision of law; and (B) special additional duties authorized for Reserves, or a member of the Space Force, by an authority designated by the Secretary concerned and performed by them on a voluntary basis in connection with the prescribed training or maintenance activities of the units to which they are assigned. Such term includes those duties when performed by Reserves in their status as members of the National Guard. **(e) Space Force.—** The following definitions relating to members of the Space Force apply in this title: (1) The term “space force active status” means the status of a member of the Space Force who is not in a space force inactive status and is not retired. (2) The term “space force inactive status” means the status of a member of the Space Force who is designated by the Secretary of the Air Force, under regulations prescribed by the Secretary, as being in a space force inactive status. (3) The term “space force retired status” means the status of a member of the Space Force who— (A) is receiving retired pay ; or (B) but for being under the eligibility age applicable under [section 12731 of this title](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title10-section12731&num=0&edition=prelim), would be eligible for retired pay under chapter 1223 of this title. (4) The term “sustained duty” means full-time duty by a member of the Space Force ordered to such duty by an authority designated by the Secretary of the Air Force— (A) in the case of an officer— (i) to fulfill the terms of an active-duty service commitment incurred by the officer under any provision of law; or (ii) with the consent of the officer; and (B) in the case of an enlisted member, with the consent of the enlisted member as specified in the terms of the member’s enlistment or reenlistment agreement. **(f) Facilities and Operations.—** The following definitions relating to facilities and operations apply in this title: (1) **Range.—** — The term “range”, when used in a geographic sense, means a designated land or water area that is set aside, managed, and used for range activities of the Department of Defense. Such term includes the following: (A) Firing lines and positions, maneuver areas, firing lanes, test pads, detonation pads, impact areas, electronic scoring sites, buffer zones with restricted access, and exclusionary areas. (B) Airspace areas designated for military use in accordance with regulations and procedures prescribed by the Administrator of the Federal Aviation Administration. (2) **Range activities.—** — The term “range activities” means— (A) research, development, testing, and evaluation of military munitions, other ordnance, and weapons systems; and (B) the training of members of the armed forces in the use and handling of military munitions, other ordnance, and weapons systems. (3) **Operational range.—** — The term “operational range” means a range that is under the jurisdiction, custody, or control of the Secretary of a military department and— (A) that is used for range activities, or (B) although not currently being used for range activities, that is still considered by the Secretary to be a range and has not been put to a new use that is incompatible with range activities. (4) **Military munitions.—** (A) The term “military munitions” means all ammunition products and components produced for or used by the armed forces for national defense and security, including ammunition products or components under the control of the Department of Defense, the Coast Guard, the Department of Energy, and the National Guard. (B) Such term includes the following: (i) Confined gaseous, liquid, and solid propellants. (ii) Explosives, pyrotechnics, chemical and riot control agents, smokes, and incendiaries, including bulk explosives and chemical warfare agents. (iii) Chemical munitions, rockets, guided and ballistic missiles, bombs, warheads, mortar rounds, artillery ammunition, small arms ammunition, grenades, mines, torpedoes, depth charges, cluster munitions and dispensers, and demolition charges. (iv) Devices and components of any item specified in clauses (i) through (iii). (C) Such term does not include the following: (i) Wholly inert items. (ii) Improvised explosive devices. (iii) Nuclear weapons, nuclear devices, and nuclear components, other than nonnuclear components of nuclear devices that are managed under the nuclear weapons program of the Department of Energy after all required sanitization operations under the Atomic Energy Act of 1954 ([42 U.S.C. 2011](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title42-section2011&num=0&edition=prelim) et seq.) have been completed. (5) **Unexploded ordnance.—** — The term “unexploded ordnance” means military munitions that— (A) have been primed, fused, armed, or otherwise prepared for action; (B) have been fired, dropped, launched, projected, or placed in such a manner as to constitute a hazard to operations, installations, personnel, or material; and (C) remain unexploded, whether by malfunction, design, or any other cause. (6) **Energy resilience.—** — The term “energy resilience” means the ability to avoid, prepare for, minimize, adapt to, and recover from anticipated and unanticipated energy disruptions in order to ensure energy availability and reliability sufficient to provide for mission assurance and readiness, including mission essential operations related to readiness, and to execute or rapidly reestablish mission essential requirements. (7) **Energy security.—** — The term “energy security” means having assured access to reliable supplies of energy and the ability to protect and deliver sufficient energy to meet mission essential requirements. (8) **Military installation resilience.—** — The term “military installation resilience” means the capability of a military installation to avoid, prepare for, minimize the effect of, adapt to, and recover from extreme weather events, anticipated or unanticipated changes in environmental conditions, energy or water disruptions, or human-induced hazards with respect to the environment, that do, or have the potential to, adversely affect the military installation or essential transportation, logistical, or other necessary resources outside of the military installation that are necessary in order to maintain, improve, or rapidly reestablish installation mission assurance and mission-essential functions. **(g) Rules of Construction.—** In this title— (1) “shall” is used in an imperative sense; (2) “may” is used in a permissive sense; (3) “no person may * * *” means that no person is required, authorized, or permitted to do the act prescribed; (4) “includes” means “includes but is not limited to”; and (5) “spouse” means husband or wife, as the case may be. **(h) Reference to Title 1 Definitions.—** For other definitions applicable to this title, see sections 1 through 5 of title 1.