Generally, an alien must present a valid, unexpired visa in the category for which application for admission is being made, each time s/he enters the United States (unless exempt from the visa requirement). If an alien's nonimmigrant visa expires while s/he is in the U.S., or if an alien changes her/his nonimmigrant status in the US, the next time they travel abroad they must obtain a new visa in the proper category to be readmitted to the US.

An exception to this rule exists for H-1B, E-3, TN or O-1 nonimmigrants who travel for less than 30 days solely to Canada or Mexico." The visas of such aliens are considered to be "extended" to the date of re-entry, eliminating the need to obtain a new visa at a U.S. consulate before that particular reentry.

This benefit also applies to nonimmigrants who have changed nonimmigrant status in the U.S., whose visa is still in the category in which they had entered the U.S. In that case, the visa is considered "converted" to the proper visa category as well as "extended" to allow reentry.

22 CFR 41.112(d) provides:

(ii) In cases where the original nonimmigrant classification of an alien has been changed by DHS to another nonimmigrant classification, the validity of an expired or unexpired nonimmigrant visa may be considered to be automatically extended to the date of application for readmission, and the visa may be converted as necessary to that changed classification.

An individual whose visa is in an expired passport or a different kind of passport (e.g. official passport v. regular passport) can also benefit from this provision, provided both passports were issued by the same country, and the individual actually carries the other passport that contains his or her original nonimmigrant visa at the time of reentry. Citizens of countries that keep the old passport upon issuance of a new one are therefore at a disadvantage when traveling to contiguous territories.

If you are a national of Iran, Syria, Sudan or Cuba you are not eligible to reenter the U.S. with Automatic Visa Revalidation

 Eligibility for automatic extension of validity at ports of entry

The automatic extension of validity at ports of entry benefit is only available to a nonimmigrant who:

  • Was admitted to the United States on the basis of a nonimmigrant visa
  • Has a Form I-94 valid for an unexpired period of admission or extension of stay
  • If the individual had been issued a paper Form I-94 (e.g., had last entered the US prior to I-94 automation), a paper form must be presented to comply with revalidation requirements
  • If the individual had been admitted with an electronic I-94, it will be best if s/he travels with a print-out of the I-94 record; that electronic I-94 record will be revalidated to reflect the new entry, on the same electronic I-94 record.
  • If in a petition-based category such as H-1B or O-1, has a current Form I-797 approval notice.
  • Is applying for readmission after an absence not exceeding 30 days solely in Canada or Mexico  
  • Has maintained and intends to resume nonimmigrant status.
  • Is applying for readmission within the authorized period of initial admission or extension of stay.
  • Has a valid passport.
  • Has not applied for a new visa during this particular trip
  • Is not inadmissible as a nonimmigrant under INA § 212
  • Has never had a visa canceled under INA § 222(g)
  • Is not a citizen or national of a country that has been designated as a "state sponsor of terrorism" (currently Iran, Syria, and Sudan)

An individual who meets these criteria should be permitted to re-enter the US as though s/he had never left. If you have changed your immigration status in the US then you should be readmitted in the changed classification. You must present an original Form I-94 (either online or at the bottom of your Approval Notice from USCIS). The Form I-94 presented must be valid - it cannot have expired or be for an incorrect nonimmigrant status. For example, an individual who is in F-1 status and who has applied for but not yet received a change of status to H-1B status would not be considered eligible to leave and return to the U. S. through this process.