People having a non-immigrants status while traveling in the United States on temporary visas must be very careful when considering the dates and longevity of their authorized stay. The ending date can be easily found on the arrival/departure record or it can even be stamped on your passports. If you decide to stay in the United States beyond the ending date, this will automatically cause you to be out of status.
Please, keep in mind that the validity of a visa and the duration of your stay in the U.S. are not the same thing. Your visa might be valid for a 2-year period but, you might not be allowed to stay more than three months at a time once you travel and enter the United States.
Being out of status means you have violated the U.S. immigration laws. You automatically become ineligible for U.S. visas in future and also, you may not be able to travel back to the U.S. anymore.
If you need to stay a little longer in the United States, you must either file an application to extend or you can change your non-immigrant status, prior to the expiration of his authorized period of stay.
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