Social Security number

American  

[soh-shuhl si-kyoor-i-tee nuhm-ber] / ˈsoʊ ʃəl sɪˈkyʊər ɪ ti ˌnʌm bər /

noun

1. a unique nine-digit number assigned to each U.S. citizen and sometimes also given to resident non-citizens, used by the government for Social Security taxes, program eligibility, etc. SSN

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Etymology

Origin of Social Security number

First recorded in 1935–40

Example Sentences

To find your record, you’ll need to provide your full name, date of birth, state driver’s license or identification card number and the last four digits of your Social Security number.

From Los Angeles Times • May 28, 2026

Babies born from 2025 to 2028 who are American citizens and have a Social Security number are eligible for the seed money.

From Barron's • May 28, 2026

Children born between 2025 and 2028 who are U.S. citizens and have a Social Security number are eligible for $1,000 in seed money from the federal government.

From The Wall Street Journal • May 27, 2026

A secure portal also beats emailing documents directly to your preparer, since forms often include your Social Security number and other sensitive financial information.

From MarketWatch • Apr. 1, 2026

He steps out of the office, leaving me with a form: name, address, Social Security number.

From "It’s Kind of a Funny Story" by Ned Vizzini