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

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

They need to be U.S. citizens with a valid Social Security number.

From MarketWatch • May 28, 2026

Make sure your voter registration is current by entering your name, date of birth and identification or Social Security number on the secretary of state’s website.

From Los Angeles Times • May 1, 2026

In addition, make sure your name, tax year and Social Security number are on the reply.

From The Wall Street Journal • Mar. 20, 2026

We would attempt to say, “Correction-officer recruit,” and our name and Social Security number, during which time we would presumably learn how effective the gas was.

From "Newjack: Guarding Sing Sing" by Ted Conover