In order to qualify for U nonimmigrant status, typically referred to as a U visa, you must meet the basic eligibility requirements as outlined at "U Visas for Crime Victims Assisting Law Enforcement: Who Is Eligible." One important requirement is that you are either admissible to the U.S. or request a waiver of inadmissibility.
A person may be inadmissible for various health, criminal, security, or other grounds. For more information on what makes a person inadmissible, see Nolo's article "Inadmissibility: When the U.S. Can Keep You Out." This article discusses how to apply for a waiver of inadmissibility if you are applying for U status.
When applying for an immigration benefit, there are many grounds of inadmissibility that cannot be set aside, even with a waiver. What sets the U visa apart from many other immigration applications, however, is that most grounds of inadmissibility can be waived, except for participation in Nazi persecution, genocide, or committing any act of torture or extrajudicial killing.
This means that even if you entered the U.S. without inspection multiple times or have a final order of removal against you -- which would make most applicants for immigration benefits "inadmissible" -- you may still be able to apply for a waiver that will enable you to obtain a U visa.
In order to request a waiver, you will need to file Form I-192, Application for Advance Permission to Enter as a Nonimmigrant, along with your U visa application. You must also establish that it is in the public or national interest for U.S. Citizenship and Immigration Services (USCIS) to grant this waiver. The decision to approve this waiver is completely discretionary, which means USCIS officials can ultimately decide whether or not you deserve the waiver.
Attorneys and advocates who assist U visa applicants generally consider the I-192 waiver application as presenting a balancing test to USCIS, which means that you should provide any and all information that might tip the scales in your favor. Successful waiver applicants will show that the positive factors in the waiver application outweigh any inadmissibility issues and will demonstrate to USCIS that it is in the public or national interest to grant the waiver.
Potential positive factors include your helpfulness to law enforcement, any trauma you suffered as a victim of a serious crime, U.S. ties such as family members and community engagement, and any hardship you might suffer if forced to return to your country of origin.
USCIS has also emphasized the importance of showing remorse and rehabilitation when appropriate with regards to any criminal issues or immigration violations as a positive factor in your application.
If your only ground of inadmissibility is a single unlawful entry, the merits of your U visa application will most likely be sufficient to outweigh that one act. Little, if any, additional evidence will likely be needed to support your waiver application.
If, however, you have triggered other grounds of inadmissibility or have multiple inadmissibility issues, you will have to provide additional evidence to establish that you deserve the waiver. If you have a health-related ground of inadmissibility, for example, you may want to provide evidence that you would suffer hardship in your home country because you would not have access to medical treatment such as you receive here. (This is in addition to providing proof of other positive factors as mentioned above, such as family ties and so forth.)
If you are inadmissible to the U.S. due to a record of criminal convictions, USCIS will consider both the number and the seriousness of the offenses that you committed and weigh them against the positive factors in your application.
In cases involving violent or dangerous crimes or involving the security grounds related to terrorism, waivers are approved only in extraordinary circumstances. For example, if your assistance is needed in a high-profile criminal investigation, it might be in the national interest for USCIS to grant a waiver in order for you to obtain a U visa.
Putting together an I-192 waiver application, especially when dealing with the more serious inadmissibility grounds, can be a complex process. An experienced immigration attorney can help you determine which grounds of inadmissibility may apply in your situation and assist you in assembling a successful U visa application with an I-192 waiver.