In the immigration laws of the United States, a non-citizen who applies for entry into the United States or applies for an immigration status while already living in the United States are subject to a determination whether they are admissible into the country. Rather than defining who is admissible into the United States, the Immigration and Nationality Act defines who is inadmissible to receive a visa and be eligible for admission.
The grounds of inadmissibility are divided in the following categories: a few examples under each category are cited.
1. Health - medical history that include some communicable diseases or illnesses that will pose as a public charge ...
Pursuant to Immigration and Nationality Act Section 212(a), 8 U.S.C. 1001, et. seq., as amended, when an alien applies for a visa to enter the United States, the government identifies who will not be approved because of inadmissible grounds. In other words, who the government will allow to enter the United States. There are several categories described with examples of grounds of inadmissibility. Some of the grounds of inadmissibility may not apply like refugees who enter the United States without concern about the public charge issue. For other grounds of inadmissibility, a waiver is available.