Is the social security card number 9 digits or 19 digits?

Cards are not 9 pairs, nor are they 19 pairs.

The social security card number generally consists of 18 digits, which is the same as the cardholder's ID number. The social security card is the electronic certificate for cardholders to enjoy social security and public employment services. It has the basic functions of information recording, information inquiry and business handling.

The social security card records basic identity information, insurance information, payment records, etc. The first 17 digits of its number are the personal identity card number of the insured, and one digit is the special check code.