If you have an expired visa stamp but you are still on a valid I-94 you may be able to reenter the US invoke Automatic Revalidation (“AVR”) of your visa. You must meet certain requirements, including but not limited to: 1. You left the USA for a period of 30 days or less for a brief travel to Canada, Mexico or Adjacent Islands. 2. You have valid admission stamp or paper/online Form I-94, Arrival/Departure Record 3. You have a valid passport  4. You have an expired visa stamp To find out more: https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/visa-expiration-date/auto-revalidate.html