Upon arrival in the U.S. each person must undergo Customs and Immigration inspection. A U.S. Customs Inspector will examine your luggage to determine compliance with regulations concerning the items that you carry. Generally, you may bring with you any items for your personal use. Prohibited possessions include some foodstuffs, narcotics, items for resale, etc. For more information on Customs regulations, visit https://www.cbp.gov/travel/international-visitors or consult the U.S. Customs and Border Protection Question-and-Answer webpages.
At the time of your arrival inspection, you will be required to present your passport (with the appropriate visa stamp), your Certificate of Eligibility (I-20 or DS-2019) and financial documentation. If you are Canadian, you will be asked to complete an Arrival/Departure Record (I-94) as well. The Immigration Inspector will stamp the form, indicating the date and place of your entry, and will indicate that you are admitted for “D/S” (Duration of Status).
If you hold an F-1 or J-1 visa, D/S means that you are permitted to stay in the U.S. as long as you are a full-time student pursuing a degree, but no later than the expected date of completion on your Form I-20 or DS-2019 plus any number of days granted as a grace period according to the terms of your student status. Procedures exist to extend your Certificate of Eligibility if further time is required to complete your program. You should inquire about extension procedures as the date approaches.
The Immigration Inspector will process your Certificate of Eligibility and return the student copy to you. Your I-20 or DS-2019 and the I-94 card should be kept in a safe place and carried with you when traveling.