"Status" in the immigration context refers to an individual's legal position with regard to their presence in the U.S. "In status" means that an individual has a legal right to be present in the U.S. under existing law, and "out of status" means that an individual does not currently have a legal right to be present in the U.S.
Does a person have to have a visa or a green card to be "in status?"
A person can be "in status" in a number of different ways, among them: by having U.S. citizenship, by having permanent residence (a "green card"), by having a valid unexpired non-immigrant visa (there are several types of these) without having violated the terms of the visa, by having been Paroled into the U.S., by being granted refugee or asylee status, etc.
If a foreign national's nonimmigrant visa has not yet expired, doesn't this mean that they are still in status?
Not necessarily. While expiration of a nonimmigrant visa's validity period does leave a foreign national out of status, a foreign national can also become out of status by violating the terms of his or her nonimmigrant visa. This may or may not be the fault of the foreign national.
For instance, the terms of a B-1/B-2 visitor visa require that the foreign national not work; working while in the U.S. violates the terms of this visa. The terms of an H-1B require that the foreign national remain employed by the petitioning company or organization - the terms of the H-1B are violated even if the foreign national is laid off by the employer through no fault of his or her own.
Does the fact of a foreign national being "in status" automatically mean that the foreign national has a right to work?
Not necessarily. Even within the category of non-immigrant visas, some (like the H-1B or L-1 for instance) carry the right to work while here "incident to status" - and only for the petitioning employer -while some (like the B-1/B-2) do not and some (like the F-1) only carry the right to work in certain circumstances and/or with additional approval required.
Once a foreign national is out of status, is there any way to get back into a legal status?
Only in a few very limited circumstances, the main ones being by filing and Adjustment of Status application based on marriage to a U.S. citizen and/or through 245(i) eligibility.
Assuming these do not apply, once an individual has become out of status through expiration of one nonimmigrant visa, the only way to regain valid legal nonimmigrant status is to leave the U.S. and re-enter.
This course of action often leaves a foreign national in an impossible situation: in some cases the very act of leaving the U.S. can subject the foreign national to the three- or ten-year bar to reentry. Once an individual is out of status, it is critical that the individual contact us or other qualified immigration counsel before making a decision to file any kind of immigration application or depart from the U.S.