United States Army Reserve The United States Army Reserve ( USAR ) is the federal reserve force of the United States Army . Together , the Army Reserve and the Army National Guard constitute the Army element of the Reserve components of the United States Armed Forces . On 9 June 2012 , Lieutenant General Jeffrey W . Talley became the 32nd Chief of Army Reserve , and Commanding General , United States Army Reserve Command ( USARC ) . On 2 November 2012 , Command Sergeant Major James Lambert was sworn in as the Interim Command Sergeant Major of the Army Reserve , serving as the Chief of the Army Reserve ' s senior advisor on all enlisted soldier matters , particularly areas affecting training , leader development , mobilization , employer support , family readiness and support , and quality of life . History . In 1908 Congress created the Medical Reserve Corps , the official predecessor of the Army Reserve . After the First World War , under the National Defense Act on 4 June 1920 , Congress reorganized the U . S . land forces by authorizing a Regular Army , a National Guard , and an Organized Reserve ( Officers Reserve Corps and Enlisted Reserve Corps ) of unrestricted size , which later became the Army Reserve . This organization provided a peacetime pool of trained Reserve officers and enlisted men for use in war . The ORC included the Officers ’ Reserve Corps , Enlisted Reserve Corps and Reserve Officers Training Corps . The Organized Reserves were redesignated 25 March 1948 as the Organized Reserve Corps . Recognizing the importance of the Organized Reserve to the World War II effort , Congress authorized retirement and drill pay for the first time in 1948 . A tentative troop basis for the Organized Reserve Corps , prepared in March 1946 , outlined 25 divisions - 3 armored , 5 airborne , and 17 infantry . These divisions and all other Organized Reserve Corps units were to be maintained in one of three strength categories , labeled Class A , B , and C . Class A units were divided into two groups , one for combat and one for service , and units were to be at required table of organization strength ; Class B units were to have their full complement of officers and enlisted cadre strength ; and Class C were to have officers only . The troop basis listed nine divisions as Class A , nine as Class B , and seven as Class C . Porter therefore proposed reclassification of all Class A divisions as Class B units . Eventually the War Department agreed and made the appropriate changes . Although the dispute over Class A units lasted several months , the War Department proceeded with the reorganization of the Organized Reserve Corps divisions during the summer of 1946 . That all divisions were to begin as Class C ( officers only ) units , progressing to the other categories as men and equipment became available , undoubtedly influenced the decision . Also , the War Department wanted to take advantage of the pool of trained reserve officers and enlisted men from World War II . By that time Army Ground Forces had been reorganized as an army group headquarters that commanded six geographic armies . The armies replaced the nine corps areas of the prewar era , and the army commanders were tasked to organize and train both Regular Army and Organized Reserve Corps units . The plan the army commanders received called for twenty - five Organized Reserve Corps divisions , but the divisions activated between September 1946 and November 1947 differed somewhat from the original plans . The First United States Army declined to support an airborne division , and the 98th Infantry Division replaced the 98th Airborne Division . After the change , the Organized Reserve Corps had four airborne , three armored , and eighteen infantry divisions . The Second Army insisted upon the number 80 for its airborne unit because the division was to be raised in the prewar 80th Division ' s area , not that of the 99th . Finally , the 103rd Infantry Division , organized in 1921 in New Mexico , Colorado , and Arizona , was moved to Iowa , Minnesota , South Dakota , and North Dakota in the Fifth United States Army area . The Seventh Army ( later replaced by Third Army ) , allotted the 15th Airborne Division , refused the designation , and the adjutant general replaced it by constituting the 108th Airborne Division , which fell within that component ' s list of infantry and airborne divisional numbers . Thus the final tally of divisions formed after World War II appears to have been the 19th , 21st , and 22d Armored Divisions ; the 80th , 84th , 100th and 108th Airborne Division s ; and the 76th , 77th , 79th , 81st , 83d , 85th , 87th , 89th , 98th , 90th , 91st , 94th , 95th , 96th , 97th , 102nd , 103rd , and 104th Infantry Division s . A major problem in forming divisions and other units in the Organized Reserve Corps was adequate housing . While many National Guard units owned their own armories , some dating back to the nineteenth century , the Organized Reserve Corps had no facilities for storing equipment and for training . Although the War Department requested funds for needed facilities , Congress moved slowly in response . During the summer and fall of 1951 the six army commanders in the United States , staff agencies , and the Section V Committee , created after World War I for the reserve components to have a voice in their affairs , evaluated Department of the Army reorganization plans for the ORC . The army commanders urged that all divisions in the Organized Reserve Corps be infantry divisions because they believed that the reserves could not adequately support armored and airborne training . They thought thirteen , rather than twelve , reserve divisions should be maintained to provide a better geographic distribution of the units . The Section V Committee opposed the reduction of the Organized Reserve Corps from twenty - five to thirteen divisions because it feared unfavorable publicity , particularly with the nation at war . On 20 December the Vice Chief of Staff of the Army , General John E . Hull , directed the reorganization and redesignation of airborne and armored divisions as infantry as soon as practicable . In March 1952 the 80th , 84th , 100th , and 108th Airborne Divisions were reorganized and redesignated as infantry divisions , and the 63d , 70th , and 75th Infantry Division s replaced the 13th , 21st , and 22d Armored Divisions . Before the dust had settled on the reforms , the Army realized that it had failed to improve unit manning or meet reasonable mobilization requirements . In the fall of 1952 Army leaders thus proposed that the personnel from the thirteen inactivated Army Reserve divisions be assigned to strengthen the remaining twelve divisions . To keep the unneeded fifteen Army Reserve divisions active , they were to be reorganized as training divisions to staff training centers upon mobilization or man maneuver area commands for training troops . The continental army commanders implemented the new Army Reserve troop basis in 1955 piecemeal . They reorganized , without approved tables of organization , the 70th , 76th , 78th , 80th , 84th , 85th , 89th , 91st , 95th , 98th , 100th , and 108th Infantry Divisions as cadre for replacement training centers and organized the 75th " Maneuver Area Command " using the resources of the 75th Infantry Division . Two years later the 75th Infantry Division was inactivated along with 87th Infantry Division . Assets of the 87th were used to organize a maneuver area command ; thus one unneeded division remained in the troop basis . While the Korean War was still underway , Congress began making significant changes in the structure and role of the Army Reserve . These changes transformed the Organized Reserve into the United States Army Reserve , seemingly from 9 July 1952 . This new organization was divided into a Ready Reserve , Standby Reserve , and Retired Reserve . Army Reserve units were authorized twenty - four inactive duty training days a year and up to seventeen days of active duty ( called annual training ) . In 1959 the Army decided to realign National Guard and Army Reserve divisions under Pentomic structures . Secretary of Defense Neil H . McElroy decided on 10 Army Reserve divisions . By October 1959 ten Army Reserve infantry divisions completed their transition , but at a reduced strength . The eleventh combat division , the 104th , in the Army Reserve was converted to training , for a total of thirteen training divisions , all of which were in the Army Reserve . To reorganize the Army Reserve to the new ROAD structures in the early 1960s , the Army Staff decided to retain one Army Reserve division in each of the six Army areas and to eliminate four divisions . Army commanders selected the 63d , 77th , 81st , 83d , 90th , and 102d Infantry Divisions for retention and reorganized them under ROAD by the end of April 1963 . Each division had two tank and six infantry battalions . With the elimination of the 79th , 94th , 96th , and 103d Infantry Divisions , the Army decided to retain their headquarters as a way to preserve spaces for general and field grade officers . It reorganized the units as operational headquarters ( subsequently called command headquarters [ division ] ) and directed them to supervise the training of combat and support units located in the former divisional areas and to provide for their administrative support . Some former divisional units assigned to the four divisions were used to organize four brigades , which added flexibility to the force as well as provided four general officer reserve billets . In January and February 1963 the 157th , 187th , 191st , and 205th Infantry Brigade s were organized with headquarters in Pennsylvania , Massachusetts , Montana , and Minnesota , respectively . The designation of each brigade was derived from the lowest numbered infantry brigade associated with the division under the square structure . As with the Regular Army brigades , the number and type of maneuver elements in each Army Reserve brigade varied . In November 1965 , a long - standing controversial goal of the Defense Department , a reduction of the reserve troop basis , was achieved . Those reserve units that were judged unnecessary and others that were undermanned and underequipped were deleted and their assets used to field contingency forces . Among the units inactivated were the last six combat divisions in the Army Reserve - the 63d , 77th , 81st , 83d , 90th , and 102d Infantry Divisions - and the 79th , 94th , and 96th Command Headquarters ( Division ) . The 103d Command Headquarters ( Division ) was converted to a support brigade headquarters . Reserve service today . Reserve soldiers perform only part - time duties as opposed to full - time ( " active duty " ) soldiers , but rotate through mobilizations to full - time duty . When not on active duty , reserve soldiers typically perform training / service one weekend per month , currently referred to as " Battle Assembly " , and for two continuous weeks at some time during the year referred to as " Annual Training " ( AT ) . Many reserve soldiers are organized into Army Reserve troop program units ( TPU ) , while others serve in active Army units as Individual Mobilization Augmentees ( IMA ) , or are in non - drilling control groups of the Individual Ready Reserve ( IRR ) . Reserve Soldiers may also serve on active duty in support of the US Army Reserve ( USAR ) in an Active Guard / Reserve ( AGR ) status . All United States Army soldiers sign an initial eight - year service contract upon entry into the military . Typically , the contract specifies that some of the service will be in the Regular Army ( also called " Active Component " / AC ) for two , three , or four years ; with the remaining obligation served in the Reserve Component ( RC ) . Some Soldiers elect to sign contracts specifying that all eight years be served in the RC . Soldiers entering directly into the U . S . Army Reserve nevertheless spend a period of initial active duty ( approximately five months depending upon Military Occupational Specialty ( MOS ) ) for basic training and Advanced Individual Training ( AIT ) . All U . S . Army Reserve soldiers are subject to mobilization throughout the term of their enlistment . Soldiers who , after completing the AC portion of their enlistment contract choose not to re - enlist on active duty , are automatically transferred to the RC to complete the remainder of their " Statutory Obligation " ( eight - year service total ) and may be served in a drilling Troop Program Unit ( TPU ) , Individual mobilization Augmentee ( IMA ) , or Individual Ready Reserve ( IRR ) status . Commissioned officers , Warrant Officers , and Non - commissioned officers of the rank of Staff Sergeant ( E - 6 ) and above are considered to be on indefinite status if they have more than 10 years of service . ( This no longer applies to reenlist with an " Indefinite " status as part of the Army Reserve . Memo is dated 20080110 – It is not retroactive . ) The Army Reserve was composed of 205 , 000 soldiers as of 2009 . Importance to the active army . In the early 1980s , Army Reserve soldiers constituted the following numbers in US Army units : In 1980 , the peacetime USAR chain of command was overlaid with a wartime trace . In an expansion of the roundout and affiliation programs begun ten years earlier , CAPSTONE purported to align every Army Reserve unit with the active and reserve component units with which they were anticipated to deploy . Units maintained lines of communication with the units – often hundreds or thousands of miles away in peacetime – who would presumably serve above or below them in the event of mobilization . This communication , in some cases , extended to coordinated annual training opportunities . Despite the commonly held belief that CAPSTONE traces were set in stone , the process of selecting units to mobilize and deploy in 1990 and 1991 in support of Operation Desert Shield and Desert Storm largely ignored CAPSTONE . In the post - Cold War draw - down , all of the Army Reserve ' s combat units were disbanded , except the 100th Battalion , 442nd Infantry Regiment . This meant the disestablishment of the three remaining Army Reserve fighting brigades : the 157th Infantry Brigade ( Mechanized ) ( Separate ) of Pennsylvania , the 187th Infantry Brigade ( Separate ) of Massachusetts , and the 205th Infantry Brigade ( Separate ) ( Light ) of Minnesota . Many of the Army Reserve training divisions were realigned as institutional training divisions . With the Army National Guard providing reserve component combat formations and related combat support units , the Army Reserve is configured to provide combat support , combat service support , peacekeeping , nation - building and civil support capability . With roughly twenty percent of the Army ' s organized units and 5 . 3 percent of the Army ' s budget , the Army Reserve provides about half of the Army ' s combat support and a quarter of the Army ' s mobilization base expansion capability . In 2008 , the Army Reserve contains the following percentages of the Army ' s units of each category : In fiscal years 2007 – 2009 , the Army Reserve was realigned into a functional command structure . The majority of Army Reserve units are now assigned to operational and functional commands . Operational commands are deployable elements which command deployable units of the same or similar capabilities regardless of peacetime geographic location . For instance , the 377th Sustainment Command ( Theater ) commands all Army Reserve sustainment units , while the 11th Aviation Command commands all Army Reserve aviation assets . Likewise , functional commands are responsible for command of units of the same or similar capabilities regardless of peacetime geographic location , but are not , as a headquarters , deployable . The training structure has been transformed in order to streamline command and control . Instead of multiple training divisions , each with its own geographic area of responsibility , the new structure features four training commands responsible for specific categories of training throughout the United States . Each command is configured for either initial entry training , advanced individual training schools , leader development or battle command training . These commands train soldiers of the Army Reserve , Army National Guard and the active component , through formal classroom and “ hands on ” training . Two training support commands under the First United States Army , designated First Army East and First Army West , provide customized , realistic unit - specific and operation - specific training . Training Support Commands ( TSC ) plan , conduct and evaluate training exercises for Army , Army Reserve and Army National Guard units . TSC are organized under the United States First Army into two subordinate units . As a part of this realignment , most of the regional readiness commands were eliminated , leaving only seven globally . These were redesignated " [ regional , civil or mission ] support commands " ; the four in the Continental United States being " regional " ; the geography for which each regional support command increased significantly , but all of the support commands were stripped of their former command and control authority over units in their respective territories . Instead , the support commands provide base operations and administrative support to Army Reserve units within their geographic region . Current formations and units . Headquarters Commands . Office of the Chief , Army Reserve ( OCAR ) at The Pentagon , Washington , DC OCAR provides the Chief , Army Reserve ( CAR ) with a staff of functional advisors who develop and execute Army Reserve plans , policies and programs , plus administer Army Reserve personnel , operations and funding . The CAR is responsible for plans , policies and programs affecting all Army Reserve Soldiers , including those who report directly to the Army . OCAR is composed of specialized groups that advise and support the CAR on a wide variety of issues . United States Army Reserve Command ( USARC ) at Fort Bragg , North Carolina Through USARC , the CAR commands all Army Reserve units . USARC is responsible for the staffing , training , management and deployment of its units to ensure their readiness for Army missions . The Army Reserve consists of three main categories of units : operational and functional , support , and training . Due to Base Realignment and Closure Act , the headquarters of USAR has moved to Ft . Bragg . Other components . The Army of the United States is the official name for the conscripted force of the Army that may be raised at the discretion of the United States Congress , often at time of war or mobilization for war . The last use of the Army of the United States was in 1974 .