It used to be 18 years old. But today there is on Draft in the USA, so no registration is required.
Vietnam was the last war to use the draft in the USA.
When they are 18
The selective service act is the requirement of all young men to register by the time they turn 18, with selective service, in the event of a draft.
Almost all males ages 18 to 25 are required to register for Selective Service. Visit their website for more information.
when must all men register for selective service
Incase the Draft is called.
They were required to register for military service.
Currently all males between the ages of 18 and 25 must register with the selective service SSS Gov. Only those who are US citizens or Green Card holders need to register.
18 years old
Who Must Register?Male US citizens (regardless of where they live) and male permanent resident aliens living in the US who were born after December 31, 1959 are required to register with Selective Service within 30 days of their 18th birthday (30 days before and after). If you fail to register during this time period, you may submit a late registration up until your 26th birthday.
The Selective Service Act is a law in the United States that requires all male citizens and immigrants aged 18 to 25 to register with the Selective Service System. In the event of a national emergency, this system can be used to draft individuals into the military.
21 to 31
Most males are required to register for the selective service when they turn 18. In case of an emergency they can be called for a military draft.