In reserve duty (or reserve service; Hebrew: שירות מילואים, Sherut Miluim), Israeli residents who have completed military service are assigned to the Israel Defense Forces' military reserve force to provide reinforcements during emergencies (war, military operations or natural disasters), and as a matter of routine course (e.g. for training, ongoing security and other activities). Some reservists are assigned to the same units they served in during their regular military service, and some are assigned to dedicated reserve units.
Within the IDF's Manpower Directorate, the professional officer in charge of the reserve army is the chief reserve officer (abbreviated קמל"ר; "Kamlar"), an officer with the rank of Brigadier General.
For many years, reserve service had been implemented under the "Defense Service Law", but since 1 August 2008 it has been implemented mainly under the "Reserve Service Law".
From 2004 onwards Israel has marked "Yom Miluim" ([National] Reserve Day) on the Lag BaOmer holiday to promote public sympathy for and appreciation of the soldiers serving in the reserve forces.
Reserve service is mandatory in Israel, and is considered part of the national ethos. The actual percentage serving in the IDF reserves has significantly dwindled over the years, and nowadays consists mainly of soldiers who served in one of the IDF combat units during their initial compulsory service. This reality leads in many instances to feelings of deprivation among the IDF reservists.
In the past, the age of exemption from reserve duty by the Defense Service Law (חוק שירות ביטחון [נוסח משולב], התשמ"ו-1986) was 54 for men and 38 for women; nevertheless, it was not possible to call up reservists over 41 years of age who had served in a combat unit in the last 10 years or more, or reserve soldiers over the age of 48 who had served in a combat unit for at least 20 years, unless they gave consent for this to happen. Over the years, the IDF has lowered the maximum age at which male reservists are called for reserve duty service, so that the earliest age of exemption for males has become 40 for regular soldiers, 42 for combat officers, 45 for non-combat officers, 48 for soldiers serving in the Regional Defense units (הגמ"ר) and in non-military reservist units, and 51 years-of-age for the reservists serving as physicians in their reserve duty. In 2008 the Knesset approved the Reserve Service Law (חוק שירות המילואים, התשס"ח-2008) which came into effect on 1 August 2008. Accordingly, the age of exemption from reserve duty was reduced for all males, and as a result, ever since then it has stood at 40 for all soldiers, 45 for officers, and 49 for reservists who perform certain specific duties defined as such by the Minister of Defense and approved by the Foreign Affairs and Defense Committee (this mostly includes officials in the medical branch, drivers of heavy equipment, mechanics and technicians).