This benefit allows certain nonimmigrants with expired visas to re-enter the U.S. after visiting a “contiguous territory” for 30 days or less.
Contiguous territories include Canada, Mexico and adjacent islands including Saint Pierre, Miquelon, the Dominican Republic, Haiti, Bermuda, the Bahamas, Barbados, Jamaica, the Windward and Leeward Islands, Trinidad, Martinique, and other British, French, and Netherlands territories or possessions in or bordering on the Caribbean Sea.
You may be eligible for automatic visa revalidation depending on your immigration status, your country of citizenship, and the length and purpose of your travel.
Department of State site
If you are trying to re-enter the U.S. using the automatic revalidation provision, you must have your printed I-94 upon re-entry. In addition, you must carry all other valid travel documents relevant to your status (passport, I-20/DS-2019 or I-797). F and J status holders must travel with a valid signature on their I-20 or DS-2019.
Dependents may re-enter the U.S. under the same guidelines as the primary status holder.
Please be aware that you are never guaranteed admission for re-entry, even if all of the above criteria are met. Customs and Border Protection (CBP) officials have discretion to approve or deny entry to anyone for reasons that may or may not be apparent to the visitor. If you are eligible for automatic visa revalidation, we recommend that you take a print out the policy to show to a CBP officer if necessary.
Travel after a change of visa status
Nonimmigrants who travel and have changed status while in the U.S., whether within a visa category (e.g., F-2 to F-1, or J-2 to J-1) or between categories (e.g., F-1 to H-1B, or F-1 to J-1), must apply for a visa in the new category in order to be readmitted.