Under U.S. visa law some people are ineligible to receive an immigrant visa and are not eligible to enter the United States unless they have obtained a waiver of the ineligibility.
These include persons who have been afflicted with a disease of public health significance, a mental disorder which is associated with a display of harmful behavior, drug addicts/abusers, and those with criminal records. Anyone who has been arrested and/or convicted of any offense, regardless of when it may have occurred, is required to declare the arrest and/or conviction.
The Rehabilitation of Offenders Act does not apply to U.S. visa law.
A determination on a person’s eligibility for a visa cannot be made until the day of the formal visa interview. If the applicant is found ineligible for a visa, the consular officer will advise the applicant if he/she is eligible to apply for a waiver of the permanent ineligibility and of the steps which must be taken to apply for and process the waiver. Further information is available from the Department of State website