Visas into the United States are complicated, and there are many different kinds. Some are permanent, such as a visa for the spouse or adopted child of a US citizen, while some are temporary, such as a student or visitor visa. The Department of Homeland Security is concerned with making sure that visas are not misused, and so have strict rules about visa applications.

In particular to be aware of is the 90-Day Rule. The 90-Day Rule states that those with temporary visas who apply for permanent residence or marry a US citizen within the first 90 days of their time in the United States are presumed to have misrepresented the reason for their original visa. The visa holder must then prove that they were honest in their original intent, and had legitimate reasons for their application for permanent residence. The rule applies to the visa holder's most recent entry into the United States. This rule can also affect the applicant if they mention that their intent with their temporary visa was to stay permanently in the US.

While the 90-Day Rule does not mean an automatic denial of an application for permanent residence, it makes the potential immigrant's process that much more difficult because of their need to prove their honesty. For those who wish to apply for permanent residence in the United States, be careful when discussing your motives for application and consider how long it has been since your most recent entry.