If you came to the United States on a tourist visa (B-2), you are expected to leave within a certain time. That time is shown on your Form I-94 Arrival/Departure Record.
However, if you believe you have some grounds upon which to obtain U.S. lawful permanent residence, you may choose to overstay while waiting for your green card. We’ll discuss here not only what normally happens when you overstay a visa, but whether people who have overstayed can ever successfully get a green card.
If you overstay a visa, it becomes legally void (automatically canceled) as of the date that you were scheduled to leave, unless you had already applied for an extension or otherwise begun the process of having your status changed. By remaining in the U.S., you violate U.S. immigration laws, most likely accrue what's known as "unlawful presence," and can be removed or subjected to future penalties.
It is important to note that if you wish to extend or change your initial visa status, you must apply prior to your permitted stay expiring – you cannot allow it to expire and then file an extension or change of status application. What’s more, you have to have valid reasons for requesting the extension or change of status. Filing a frivolous application gives you no right to remain in the United States.
The penalties get particularly harsh if you overstay a U.S. visa and therefore accrue unlawful presence of 180 days or more. If you do so, then voluntarily leave the United States and apply to return (whether on a visa or green card), you will be barred from reentry for three years. If your overstay is one year or more, you’ll face of bar on reentry of ten years. There are waivers available in certain limited circumstances.
If you’ve identified a potential basis upon which to apply for legal status in the United States, speak to an immigration lawyer immediately. Limited circumstances exist under which you could actually submit your application in the United States despite the overstay and unlawful presence and proceed to obtain a green card without having to leave the United States.
For example, someone who marries a U.S. citizen becomes an "immediate relative." This is one of the few categories of applicants allowed to apply for a green card within the United States through the process called adjustment of status. Because applicants don’t have to leave the U.S. during this process, they cannot be penalized for a lengthy visa overstay with a three-or ten-year time bar.
Or, if your overstay hasn’t yet reached six months, you might want to leave the United States before you hit that mark, in order to preserve your right to apply to return. Again, talking to a lawyer about your strategy is your best bet.