The most widely accepted forms of government-issued personal identification include driver's licenses, state identification cards and passports. Social Security cards, birth certificates and student identification cards are forms of personal identification that are accepted in certain circumstances. U.S. citizens are not required to carry identification at all times, but they must show identification in certain cases, such as during air travel.
Other forms of personal identification include Native American tribal documents, immigration or naturalization documents, and Department of Defense identification cards. These forms of identification are less common because they are not universally available.
Passports and Social Security cards are the only universal forms of identification for U.S. citizens, but state-issued identification such as a driver's license is more widely used. Passports are only issued upon request, and state laws limit the use of Social Security cards or numbers for identification in some jurisdictions.
All U.S. residents must present valid identification to obtain legal employment or travel by air. The Internal Revenue Service and Transportation Safety Administration both maintain lists of acceptable identification for these purposes. The most up-to-date versions of both lists are available on the agencies' websites. The only other time that U.S. citizens are required by law to carry personal identification is while operating a vehicle. Non-citizens must carry their immigration or naturalization documents at all times.