According to multiple sources, the size of the Israeli army is around 169,500 active military personnel. In addition, there are approximately 465,000 reserve personnel who can be called up in times of war or crisis. The Israeli army is comprised of three service branches: the Israeli Ground Forces, the Israeli Air Force, and the Israeli Navy. Military service is mandatory for all Israeli citizens over the age of 18, with some exceptions made on religious, physical, or psychological grounds. The duration of service is at least 32 months for men and 24 months for women once they enlist.