When must all men register for the Selective Service?

All men are required to register for the Selective Service at the age of 18. This requirement is part of a federal mandate to maintain a list of individuals who can be called upon for military service in times of need. Registration ensures that there is a readily available pool of individuals who can enlist if a draft is instituted. The registration process is usually straightforward and can be completed online.

The age of 18 is significant because it is the age when individuals reach legal adulthood in the United States, at which point they are able to assume legal responsibilities and rights, including the obligation to register for the Selective Service. This age requirement aligns with other civic responsibilities, such as voting, which also begins at age 18.

The options that refer to ages 16, 21, and 25 do not align with the established legislation governing Selective Service registration. Registering before age 18 is not mandated, and waiting until age 21 or beyond is too late, as the requirement is specifically set for those who turn 18.