If you are a U.S. citizen married to a foreign, and your foreign spouse is currently not permitted to remain in the U.S., you undoubtedly will be searching for a way to help him or her do so, most likely based on your marriage. "Barred" usually refers to the time bars that affect people who have overstayed a visa for more than six months and then left the United States.
Such people are prevented from returning to the U.S. for three years if their unlawful stay was between 180 and 365 days -- and for ten years if their unlawful stay lasted more than a year. If your spouse has been barred from reentering the U.S. for a certain period of time, one possible option is to seek a waiver of this time bar, in combination with the green card application, based on "extreme hardship."
In order to be eligible to file for an extreme hardship waiver, an immigrant must have a spouse (or a parent) who is a U.S. citizen or a permanent resident alien (green card holder).
The "extreme hardship" that your spouse alleges as the basis for the waiver must be a factor that substantially and directly affects the U.S. citizen or permanent resident spouse in a negative way. Whether or not an extreme hardship waiver is granted is totally up to the discretion of the officer considering the waiver application.
There are a variety of factors that an immigrant can use to demonstrate extreme hardship to the U.S. citizen or permanent resident spouse, such as:
Medical reasons – In which the immigrant is responsible for caring for an ill spouse, or certain types of treatment for the spouse are not available in the immigrant's native country.
Financial reasons – The U.S. spouse’s standard of living and income is dependent upon the immigrant remaining in the U.S. and supporting him or her.
Educational reasons – The U.S. spouse will be unable to continue or start a higher education program because it is only available in the U.S. or simply unavailable in the native country.
Personal reasons – The immigrant's removal from the U.S. would result in undue separation of spouses and/or children, based on ages and relationships, would cause the U.S. spouse to be placed in harm’s way, or would affect his or her access to social institutions or religious or cultural norms.
Other reasons - There is room for discretion and unusual circumstances in this analysis.
Then when's and how's of the application process depend on your current circumstances (for example, whether your immigrant spouse is currently in deportation proceedings), the spouse's mode of entry to the U.S. (lawful or unlawful), and more. See Staying in the U.S. With The I-601A Provisional Waiver of Inadmissibility to learn about the "stateside" waiver which allows inadmissible immigrants to apply for a waiver without leaving the country. To gain entry to the U.S., see Filing for an I-192 Waiver: "Forgiveness" of U.S. Inadmissibility.
As filing an application for an extreme hardship waiver can be complex, it is highly recommended that you contact an experienced immigration attorney for advice regarding your situation.