If the U.S. immigration authorities find you to be "inadmissible," you can be refused U.S. lawful permanent residence (a green card), as discussed in Inadmissibility: When the U.S. Can Keep You Out. However, waivers of inadmissibility are available to certain foreign nationals. A waiver means that you ask the U.S. government to overlook or forgive the ground of inadmissibility and grant the green card or other benefit despite it.
Section 212 of the Immigration and Nationality Act (I.N.A.) states which grounds of inadmissibility allow for people to make waiver applications. Some of the more common grounds of inadmissibility allowing for a waiver application are discussed below.
Note that many of them contain specific requirements as to who can apply for a waiver and on what grounds—and that you will have to submit not only a basic form request, but many documents to prove that you meet the various requirements and deserve the waiver.
Unlawful presence might be the most common ground of inadmissibility for which people file waiver applications.
If you accumulated unlawful presence in the United States and are subject to the three-year or ten-year bar, you may be able to file Form I-601, Application for Waiver of Grounds of Admissibility. However, you must have have a U.S. citizen or lawful permanent resident spouse, fiancé, or parent who would experience "extreme" hardship if you were denied admission. You cannot apply for this waiver on the basis of having a U.S. citizen or lawful permanent resident child. The application is ordinarily filed at an immigrant visa interview at an overseas U.S. consulate.
Another option is the Form I-601A, Application for Provisional Unlawful Presence Waiver, often called the provisional waiver. The advantage to this waiver is you can submit the application from within the U.S., before leaving for their consular interview, as long as you are already living the United States. Thus you avoid the risk of being barred from return based on your unlawful presence. Those who can submit it include spouses and children of permanent residents, siblings of U.S. citizens, and adult and married children of U.S. citizens. But unlawful presence must be the only ground of inadmissibility for which you need a waiver; if there are others, you're back to using the I-601 waiver.
The most difficult part of submitting a waiver application for unlawful presence is demonstrating extreme hardship. Extreme hardship is not defined in the law itself, but is understood to mean hardship greater than what a qualifying relative could be expected to experience if you were denied admission to the United States. This vague definition means that there is no right or wrong answer. However, it also means that the officer reviewing your case has broad discretion in deciding whether or not your relative's circumstances constitutes extreme hardship. The more specific unusual situations you can show, the better. See Proving "Extreme Hardship" to a U.S. Relative for Immigration Purposes.
Also consider introducing evidence of "mitigating" factors to your waiver application. Mitigating factors can turn an otherwise weak application into a successful one. These factors include children with the qualified relative, a genuine belief that you had been complying with immigration laws, and having come to the U.S. when you were a young child.
You will also want to address any factors that can be deemed "aggravating." These are factors that will weaken the overall strength of your application. They can include prior violations of immigration law or criminal charges, arrests, or convictions. They can also include factors that hint at marriage fraud. If your qualifying relative is from the same country as you or speaks your native language, these can also be viewed as aggravating factors. If you have any aggravating factors, be prepared to submit evidence that mitigates their seriousness. For example, if you have a criminal background, you will want to submit evidence showing that you completed programs or services for rehabilitation.
Another common ground of inadmissibility that allows for a waiver application is having secured an immigration benefit through fraud or misrepresentation. You will not, however, be eligible for a waiver under any circumstances if you falsely claimed to be a U.S. citizen.
Like unlawful presence waivers, you need to have a U.S. citizen or lawful permanent resident spouse, fiancé, or parent in order to qualify for this application. You are also required to show that this qualifying relative will suffer extreme hardship if you are denied admission.
Extreme hardship, mitigating factors, and aggravating factors for a waiver application under this ground of inadmissibility are the same as for unlawful presence.
If you were denied admission to the United States because of your criminal history, you might be eligible to file a waiver application. Section 212(h) of the I.N.A. identifies certain criminal grounds that allow for a waiver application. These include crimes of moral turpitude, prostitution, and a single offense of possession of 30 grams or less of marijuana. Waivers are not allowed for murder, torture, aggravated felonies or for violations of any other law regarding controlled substances. Also see Which Crimes Can Be Waived to Get a U.S. Visa or Green Card?.
If your criminal ground of inadmissibility allows a waiver application, you are eligible if one of the following applies to you:
If you are applying for a waiver based on the passage of 15 years, you will need to demonstrate that you are not a threat to U.S. safety, security, or welfare, and that you have rehabilitated. The officer will have discretion in deciding upon these factors. Your chances of success will be greater if you have not committed any other crimes in your home country during the 15-year period and you actively participated in and completed programs specific to rehabilitation.
If you are applying based on the hardship to a qualifying relative, the factors will be the same as those for waivers of unlawful presence and misrepresentation. The only difference is that U.S. citizen or lawful permanent resident children count as qualifying relatives for criminal grounds of inadmissibility.
If you are inadmissible to the United States based on one of the grounds of inadmissibility discussed here, it's a good idea to consult with an immigration attorney to determine your eligibility for a waiver and help you prepare a convincing application.