Automatic Extension of Validity at Ports of Entry

Normally a foreign national must present a valid and unexpired visa in the correct category when entering the U.S.  An exception to this policy is for non-immigrants seeking entry into the U.S. after a visit of not more than 30 days to Mexico, Canada, or adjacent islands* (except Cuba).

Conditions for Revalidation:

• Is applying for readmission after a stay of not more than 30 days in an adjacent country or island
• Is in lawful status and intends to resume that status upon return to the U.S.
• Holds a valid passport
• Has not applied for a new visa during this trip
• Is not from a country identified as a state sponsor of terrorism (Iran, Iraq, Syria, Libya, Sudan, North Korea, or Cuba)
• Is applying for readmission within the authorized period of stay, as shown on the I-94
• Has an unexpired I-20 or DS 2019 signed for travel by an international student advisor
• Is not inadmissible under I.N.A. 212 and has never had a visa canceled under I.N.A. 222(g)

When leaving the U.S. to visit Mexico, Canada or an adjacent island, keep your I-94.  It is important that you still have it when you re-enter the U.S. under the "Automatic Extension" provision.

*Adjacent islands includes 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 possession on or bordering on the Caribbean Sea.

Official citation from Code of Federal Regulations (8 CFR 41.112) about "Automatic Extension of Validity."