Serving in the Greek military is mandatory for all men over the age of 18. As of now, the service is 12 months although it used to be 9. This may change in the future depending on the military needs of the country. There are some exceptions to joining the military such as having a disability or some other physical or mental condition that would prevent you from serving or that would harm you from serving. In many cases, military can be delayed such as studying at University but the man is supposed to complete his service after his degree.