Social Security number

American  

[soh-shuhl si-kyoor-i-tee nuhm-ber] / ˈsoʊ ʃəl sɪˈkjʊər 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

---

Etymology

Origin of Social Security number

First recorded in 1935–40

Example Sentences

See Examples For:

Social Security number

But any child who is under 18 and has a valid Social Security number can sign up for a Trump account.

From MarketWatch ● Jul. 23, 2026

When it comes to the $1,000 seed money, the IRS notes that it’s for babies who are U.S. citizens and have a valid Social Security number.

From MarketWatch ● Jul. 6, 2026

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

The Social Security number turned out to be genuine and placed McCandless’s permanent residence in northern Virginia.

From "Into the Wild" by Jon Krakauer