There's an important waiver available to immigrants who would otherwise be barred from getting green cards because they're "inadmissible" for having spent time in the U.S. unlawfully. It uses Form I-601A, and is meant to promote family unity and reduce the uncertainty and risk that came with the earlier waiver application method (Form I-601). U.S. Citizenship and Immigration Services (USCIS) offers free downloads of these forms, but you'll need to pay to submit one.
The waiver, called the "provisional" or sometimes "stateside" waiver, basically allows people immigrating as relatives of U.S. citizens and permanent residents, diversity visa lottery winners, and immigrant visa applicants in other categories, to apply for a waiver of their unlawful-presence inadmissibility before leaving the United States. For most, it's a far better option than leaving the U.S. to attend their consular interview and applying only then.
This waiver has been available since 2013. Before that, applicants had no choice but to attend the consular interview, with no sense of whether their waiver might be granted, thereby putting themselves at risk of getting trapped outside the U.S. if the waiver application were denied, as discussed further in this article.
The I-601A provisional waiver is meant to deal with one and only one ground of inadmissibility found within U.S. immigration law: the one for "unlawful presence." ("Inadmissibility" means a barrier to receiving a visa or green card.)
This ground says that an applicant who has, after the age of 18, accrued unlawful presence in the U.S. of 180 days or more, but less than 365 days, and who then leaves voluntarily, is barred from returning to the U.S. for three years; while applicants who have accrued unlawful presence of 365 days or more and then left the U.S. voluntarily are barred from returning for ten years. (See Section 212 of the Immigration and Nationality Act (I.N.A.).)
Realize, however, that green card applicants can be found inadmissible for a variety of other reasons, such as commission of certain crimes or fraud, violating U.S. immigration laws, having communicable health problems; appearing likely to become public charges (needing government assistance); and so on.
The provisional waiver cannot be used to deal with any of these, and you cannot get a provisional waiver if you are inadmissible on some basis other than unlawful presence. You will instead need to seek a traditional waiver (on Form I-601), and attend your consular interview before applying or getting an answer to your waiver request. See Who Can't Get Into The United States? for an overview of the various grounds of inadmissibility.
Before the provisional waiver option became available, the only procedural choice for visa applicants who had accrued too much unlawful presence in the U.S. was to await their interview at the U.S. consulate, leave the U.S. and attend the interview, be officially found inadmissible by a U.S. consular officer, apply to USCIS for the waiver (using Form I-601), and then wait for an answer.
This process can take many months. It often leads to long periods of family separation, even in cases where the waiver is ultimately approved by USCIS, and the visa is ultimately granted by the consulate.
And, if the waiver is ultimately denied, the applicant has to wait out the required three or ten years before returning to the U.S. on any form of visa or green card.
After the initial family-based petition or self-petition (on Form I-130 or I-360) has been submitted to and approved by USCIS, the immigrating applicant will receive information from the National Visa Center (NVC) about the next steps and required processing fees. At that point, the applicant will need to advise the NVC of plans to submit a provisional waiver request to USCIS.
The applicant then submits the provisional waiver application to USCIS on Form I-601A, with accompanying documents and fee ($630 plus $85 for biometric services if under 79 years old; 2022 figures).
USCIS will advise the National Visa Center (NVC) once it approves the provisional waiver application. The case then moves forward, and the applicant can leave the United States for the consular interview knowing that (if all else is in order) there's a good chance of being approved for the immigrant visa and green card.
If USCIS denies the provisional waiver application, the applicant can reevaluate what to do, while still living with family in the United States. No appeal is available. Nevertheless, applicants are allowed to try again before the consular case has been closed. (If you haven't already consulted an attorney, this would be an excellent time to do so.)
To make use of the I-601A waiver possibility, you must meet all of the following criteria:
The application for the waiver will not only need to include Form I-601A and the fee, but copies of documents proving all of the eligibility factors on the list above, and ideally including a personal statement from you laying out the situation and describing the hardship that your documents are meant to prove. For help preparing this application, consult an experienced immigration attorney.