Nearly all males in the United States from ages 18 - 25 must register with Selective Service. This includes citizens and immigrants - documented or not.
All males must register within 30 days of their 18th birthday.
All male immigrants from 18-25 must register within 30 days of arriving in the U.S.
Women are not required to register, by law, and therefore can not be drafted.
In some states, males are automatically entered when they obtain their drivers license.
Step 1 - Review the Selective Service registration chart to see who must register.
Step 2 - Register for the Selective Service.
Step 3 - Keep your address current. Change your address when you move.
Note: Even though he is registered, a man will not automatically be inducted into the military. In a crisis requiring a draft, men would be called in a sequence determined by random lottery number and year of birth. Then, they would be examined for mental, physical, and moral fitness by the military before being deferred or exempted from military service or inducted into the Armed Forces.