Prospective immigrants and nonimmigrants must establish that they are admissible to enter the U.S. An individual must not fall under any of the grounds of inadmissibility found in the INA § 212(a) or they will be denied entry. There are many grounds of of inadmissibility. Below are a list of the most commonly encountered:

 Immigration Violation Grounds

Prior Immigration Violations

Unlawful Presence

Health Related Grounds 

Criminal Grounds