Reservist A reservist is a person who is a member of a military reserve force . They are otherwise civilians , and in peacetime have careers outside the military . Reservists usually go for training on an annual basis to refresh their skills . This person is usually a former active - duty member of the armed forces , and they remain a reservist either voluntarily , or by obligation . In some countries such as Israel , Norway , Singapore , and Switzerland , reservists are conscripted soldiers who are called up for training and service when necessary . History . Historically reservists first played a significant role in Europe after the Prussia n defeat in the Battle of Jena - Auerstedt . On 9 July 1807 in the Treaty of Tilsit , Napoleon forced Prussia to drastically reduce its military strength , in addition to ceding large amounts of territory . The Prussian army could no longer be stronger than 42 , 000 men . The " Krümpersystem " , introduced to the Prussian army by the military reformer Gerhard von Scharnhorst , arranged for giving recruits a short period of training , which in the event of war could be considerably expanded . With this the reduction of the army ' s strength did not have the desired effect , and in the following wars Prussia was able to draw up a large number of trained soldiers . By the time of the Second Reich reservists were already being given so - called " war arrangements " following the completion of their military service , which contained exact instructions relating to the conduct of reservists in time of war . By country . Germany . Every conscript which has served at least a day in the Bundeswehr is a reservist , unless he is declared ineligible for military service or has made a claim of conscientious objection . Soldiers of enlisted ranks with a limited contract ( either 4 , 8 or 12 years ) or professional soldiers , who have filled their tour of duty , are likewise part of the reserve . This is also the case for women , but on the basis of the " Soldatengesetz " ( Eng : " Soldier Bill " ) , not the " Wehrpflichtgesetz " ( " Conscription Bill " ) . Every soldier follows his rank with the initials " d . R . " ( " der Reserve " — " in the reserve " ) . So it does not affect whether the soldier is called up , placed in an inactive formation , or not . Only professional soldiers use the appellation " a . D . d . R " ( " außer Dienst , der Reserve " — " out of service , in the reserve " ) after the end of their service . All others ( part - time soldiers and conscripts ) strictly use " d . R . " until the end of their lives . Reservists are an integral part of the Bundeswehr . They are essential for the capability of the armed forces in time of war . Reservists can be active in the Bundeswehr in addition to their mandatory service . This mostly happens through ( mostly voluntarily ) military exercises or official events . Apart from that the Bundeswehr organises reservist unions as particularly representative supporting organisations of " voluntarily reservist work " . Eligibility for compulsory military service for soldiers and other servicemen of low rank ends at the end of the 45th year of age . Thereafter the conscript is no longer part of the reserve . Despite that the appellations " a . D . " and / or " d . R . " may still be used . Conscription for under - officers and officers lasts until the 60th year of age . Until the 32nd year of age every conscript is subject to military inspection . Recognised conscientious objectors , who have completed their civil service , are nonetheless part of the reserve and in the event of war will be given a suitable non - combatant role outside the Bundeswehr , such as emergency medical services , clearing debris or minesweeping . All conscripts who have not done their service belong to the " Ersatzreserve " ( replacement reserve ) . Singapore . All male able - bodied Singapore citizens and second - generation permanent residents upon reaching the age of 18 are required to serve National Service . They serve a two - year period as Full Time National Servicemen ( NSFs ) , assigned to the Singapore Armed Forces ( SAF ) , Singapore Police Force ( SPF ) , or the Singapore Civil Defence Force ( SCDF ) . When a conscript completes his full - time service , he is considered to be " operationally ready " , and is thereafter known as an Operationally - Ready National Serviceman ( NSman ) . NSmen are the equivalent of other militaries ' reservists . The difference in nomenclature is because these NSmen will form the bulk of the Singapore Armed Forces in times of war . Similarly , Operationally - Ready NSmen of the SPF and SCDF are available to be called on in time of need . Spain . Reservistas Voluntarios ( Volunteer Reservists ) provide the Spanish Armed Forces ( Army , Navy and Air Force ) branches of qualified civilian professionals essentially required for each army . The training is divided in two phases . The first stage it ' s the Basic Training in military knowledge . The time por this phase are normally two weeks . The second stage , which typical time are one week , it ' s the Specific Training , in this phase the applicant for Reservist develop the specific tasks in his military unit . When the Applicant approve the two stages acquires the Reservist title and the rank of Soldier , Sergeant or Second Lieutenant ( Alférez ) . The time of the Reservist commitment it ' s three years , with extensions until the 58 years old for Officers and NCO and 55 years old for ordinary soldiers . United Kingdom . All three branches of the British Armed Forces have volunteer reserves . Reservists hold civilian jobs and train on a stipulated number of weekends monthly . They are generally assigned to an administrative corps or specialist trade according to their occupations and location in the country . United States . All five branches of the United States armed forces have their own Reserve Forces , whose reservists can be called upon to serve anywhere at any time : There is also the United States National Guard , which is under dual Federal / State control , and is traditionally intended for homeland defense and domestic disaster relief ( although large numbers have been deployed in the War on Terror , and as such the distinction between National Guardsmen and Reservists has become blurred ) . The National Guard is divided into : During peacetime Reservists and National Guardsmen spend one weekend a month , two weeks a year annually in training . Some states also maintain non - federal state defense force s as a small reserve for their National Guard units . This units cannot be deployed beyond the border of their states and cannot be federalized .