Unfortunately.... > Unique to every individual https://www.pcworld.com/article/3004654/a-tale-of-two-women-same-birthday-same-social-security-number-same-big-

Unfortunately.... > Unique to every individual https://www.pcworld.com/article/3004654/a-tale-of-two-women-same-birthday-same-social-security-number-same-big-data-mess.html https://www.pcworld.com/article/3004654/a-tale-of-two-women-... > assigned from birth (or whenever applied for) Sort of. Mostly yes, but not for everyone. As social security and medicare are de facto insurance policies, there are populations in the U.S. which object to them, and are not required to register, and therefore do not have SSNs. The Amish are one group. https://en.wikipedia.org/wiki/Social_Security_number#Non-universal_status https://en.wikipedia.org/wiki/Social_Security_number#Non-uni... > and which never changes for the life of the person until they die. https://en.wikipedia.org/wiki/Social_Security_number#Replacement_numbers https://en.wikipedia.org/wiki/Social_Security_number#Replace... Note that one valid, accepted reason for issuing a replacement is when a duplicate has been issues. And finally, as anyone who has ever worked in records management for a large institution that happens to receive SSN information, an SSN very explicitly is not a candidate primary key for an identifier of an individual. Everyone I've met who has tried has horror stories to tell. SSNs are not primary keys for individuals in the U.S.