When a 17 year old male turns 18 they are required to enlist in the selective service system by law.  In order to get financial aid for studies at a college or university males need to sign up to the selective service system within 30 days from his 18 birthday.

The selective service system is also used for student loans, grants, job training, federal employment, and naturalization.  If a male fails to register, he will not be eligible to receive benefits that are part of being enlisted in the selective service. 

Women are excluded from the selective service because they are excluded from combat.  So if your an 18 year old male planning to get financial aid or job training, REMEMBER to sign up within 30 of your 18th birthday.