There are several different ways by which your US visa may be denied and this judgment is purely under the discretion of the consulate officer who is overseeing your application. There are some instances where a denial of a visa can be overcome as well as instances where the denial is permanent. Below is a list of reasons why your application may be denied and what you can do to prevent or remedy the denial.
Note: This is not a comprehensive list and there are other ways in which an application can be denied. Consult the embassy or consulate with jurisdiction over your region for additional information.
An application that is not entirely filled out or lacks certain supporting documentation will likely be denied by the consular officer. The best way to prevent this from happening is by ensuring that your application is complete and all documentation is included when you submit your application for a visa.
If your visa is denied for the above reasons you have one year to send in a complete application. If you do not send a complete application to the consulate within one year you will have to re-apply
Disqualification from a Visa Category
The consular officer may decide–during the course of your interview–that you do not qualify for the visa for which you are applying. This may mean that the officer believes you intend to immigrate to the United States which is not allowed with many visas. If your visa is denied for this reason you may re-apply for the visa with further evidence that shows that you do not intend to immigrate to the United States.
Insufficient Financial Support
During the US visa application process you will have to demonstrate that you can support yourself while in the United States and that the government will not have to support you. If the consular officer determines that you cannot support yourself you will be denied the visa. You may re-apply when you have proof that you will be supported in the United States.
Ways by Which You Will Be Denied a Visa without Recourse
It is very important to be truthful during all components of the visa application process. If you lie or misrepresent yourself during the application process you could, potentially, be permanently denied a visa.
When you enter the United States you will be issued a Form I-94 which will have a date on it that indicates when you are supposed to leave the country. Leaving on time is imperative because if you do not your illegal status will be considered when you apply for a visa again and is likely to preclude you from another visa.
How to Waive Ineligibility
Contact the consular office that has jurisdiction over your locale for more information on how to obtain an ineligibility waiver.