SSA will not assign an SSN to an alien in lawful immigration status in the US who does not have DHS work authorization unless the alien has a valid nonwork reason for an SSN, such as: a Federal statue or regulation that requires the alien provide his/her SSN to get the benefit or service or a State or local law requires the alien who is legally in the US provide his/her SSN to get public assistance benefits to which the alien has otherwise established entitlement and for which all other requirements have been met.