In the past, men who made aliyah were required to serve a minimum of six months in the Israeli army. Women were exempted from service if they arrived after the age of 20. With the new IDF draft policy, new male immigrants aged 22 to 26, will no longer be required to serve. However, men who do wish to serve may still volunteer.
Though many new immigrants will now be exempt from army service, the IDF believes that this new policy won’t seriously impact the overall manpower. Before the law change, many of those who were required to serve for six months, extended their service to two years.
Under this new policy those enlisting through the Garin Tzabar program will still have to enlist for the full two years, as it is a requirement of the program.
Men who move to Israel between the ages of 18 and 19 after June 1, 2015 will be required to serve for 32 months, and women will serve for two years. Men ages 20 and 21 will serve for 24 months, and women of the same age will have a one-year service.
You can find a more detailed review (in Hebrew) here.