Glossary

Naturalization

The legal process by which a lawful permanent resident becomes a U.S. citizen, involving tests, an interview and an oath.

Also called: becoming a citizen, citizenship test, oath of allegiance

Naturalization is the process through which a foreign national becomes a U.S. citizen. Congress has the power to set a "uniform Rule of Naturalization" under Article I of the Constitution.

To qualify, an applicant generally must be at least 18, have been a lawful permanent resident for five years (or three if married to and living with a citizen), have lived in the country continuously and been physically present for a required period, show good moral character, pass English and civics tests and take an oath of allegiance. Applicants file Form N-400 with U.S. Citizenship and Immigration Services, provide fingerprints and attend an interview. Military service offers shortcuts. Roughly 800,000 people are naturalized in a typical year.

Naturalized citizens have almost all the rights of native-born citizens, including the right to vote, serve on juries and sponsor relatives, with the exception of eligibility to be president. Naturalization can be revoked, "denaturalization," only in limited cases such as fraud. Debates concern the civics test, which has been revised several times, the cost and processing time, and the level of language ability. Supporters see naturalization as the culmination of assimilation, a theme with many conservatives who stress the value of the oath and allegiance. See also green card. See also birthright citizenship.

Last reviewed November 8, 2026

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Related terms

Green card The document showing lawful permanent resident status, which lets a noncitizen live and work in the U.S. indefinitely and later apply for citizenship. Birthright citizenship The rule, based on the Fourteenth Amendment, that nearly everyone born on U.S. soil is a citizen, regardless of their parents' status. Noncitizen voting Voting by people who are not U.S. citizens, which is illegal in federal elections but allowed in some local elections. Chain migration A critics' term for family-based immigration, in which citizens and residents sponsor relatives, who may later sponsor others. DACA A 2012 policy that shields certain people brought to the U.S. as children from deportation and grants work permits, renewed every two years.