If you have a son turning 18 years old and up to the age of 25, they MUST register with Selective Services.

The reason I bring this up is because my son turned 18 in September and I didn't register him and I received a letter in the mail. He didn't get in trouble but if he doesn't register then he will.

If you are a male and live in the United States the law says you have to register within 30 days of their 18th birthday. If you don't register in that time period then, technically, in violation of the law.

Registration with Selective Services does not mean they have joined the service.

Registration is in case a crisis hits the country all of a sudden, then men would be called by a random lottery and the year of birth.

There is nothing at sss.gov that say women at age 18 have to register.